Blackford County is located in the east central portion of the U.S. state of Indiana. The county is named for Judge Isaac Blackford, who was the first speaker of the Indiana General Assembly and a long-time chief justice of the Indiana Supreme Court. Created in 1838, Blackford County is divided into four townships, and its county seat is Hartford City. Two incorporated cities and one incorporated town are located within the county. The county is also the site of numerous unincorporated communities and ghost towns. Occupying only , Blackford County is the fourth smallest county in Indiana. As of the 2010 census, the county's population is 12,766 people in 5,236 households. Based on population, the county is the 8th smallest county of the 92 in Indiana. Although no interstate highways are located in Blackford County, three Indiana state roads cross the county, and an additional state road is located along the county's southeast border. The county has two railroad lines. A north–south route crosses the county, and intersects with a second railroad line that connects Hartford City with communities to the west.
Before the arrival of European-American settlers during the 1830s, the northeastern portion of the future Blackford County was briefly the site of an Indian reservation for Chief Francois Godfroy of the Miami tribe. The first European-American pioneers were typically farmers that settled near rivers where the land had drainage suitable for agriculture. Originally, the county was mostly swampland, but more land became available for farming as the marshes were cleared and drained. Over the next 30 years, small communities slowly developed throughout the county. When the county's rail lines were constructed in the 1860s and 1870s, additional communities evolved around railroad stops.
Beginning in the late 1880s, the discovery of natural gas and crude oil in the county (and surrounding region) caused the area to undergo an economic boom period known as the Indiana Gas Boom. Manufacturers relocated to the area to take advantage of the low-cost energy and railroad facilities. The boom period lasted about 15 years, and is reflected in Blackford County's population, which peaked in 1900 at 17,213. The new construction associated with the additional prosperity of the boom period caused a significant upgrade in the county's appearance, as wooden buildings were replaced with structures made with brick and stone. Much of the infrastructure built during that time remains today—including Montpelier's historic Carnegie Library and many of Hartford City's buildings in the Courthouse Square Historic District.
Agriculture continues to be important to the county, and became even more important after the loss of several large manufacturers during the 20th century. Today, 72 percent of Blackford County is covered by either corn or soybean fields; additional crops, such as wheat and hay, are also grown.
Following thousands of years of varying cultures of indigenous peoples, the historic Miami and Delaware Indians (a.k.a. Lenape) are the first-recorded permanent settlers in the Blackford County area, living on the Godfroy Reserve after an 1818 treaty. The site is located in Blackford County's Harrison Township, east of Montpelier. Although the Godfroy Reserve was allotted to Miami Indian Chief Francois (a.k.a. Francis) Godfroy, Delaware Indians were also allowed to stay there. The Miami tribe was the most powerful group of Indians in the region, and Francois Godfroy (who was half French) was one of their chiefs. By 1839, Godfroy had sold the reserve, and the Indians had migrated west. Benjamin Reasoner was the first European–American to enter future Blackford County, and its first land owner. He entered what would become Licking Township on July 9, 1831. Reasoner and his sons built the county's first mill, which was located on the family farm.
For a brief period, the land that would become Blackford County was the western part of Jay County. An act of the Indiana General Assembly, which was approved January 30, 1836, created Jay County effective after March 1, 1836. In December 1836, a motion was made in the Indiana House of Representatives to review dividing Jay County, but that resolution was not adopted. Two Blackford County communities, Matamoras and Montpelier, originally existed as part of Jay County. Both of these communities are located along the Salamonie River in what became the northeast portion of Blackford County. John Blount founded Matamoras, arriving in 1833. This village is Blackford County's oldest community, and is the site of the county's largest water mill. The mill, constructed around 1843, was considered one of the finest in the state. Blackford County's other former Jay County community is Montpelier, which is located west of Matamoras on the Salamonie River. Led by Abel Baldwin, the community was started in 1836 by groups of migrant settlers from Vermont. The Vermont natives named the settlement after the capital of their home state, Montpelier. Blackford County's Montpelier was platted in 1837 (before Matamoras), and is the county's oldest platted community.
Several sources claim Blackford County was created in 1837. However, the law was not finalized until 1838. Indiana bill of the House No. 152 was originally for the creation of a county named Windsor. The name "Windsor" was replaced with the name "Blackford" by the House of Representatives in January 1838. An "act for the formation of the county of Blackford" was approved on February 15, 1838. This act intended that the county would be "open for business" on the first Monday in April, 1838, which was April 2. However, the county was not organized. Finally, on January 29, 1839, the original February 15 act was amended, stating that Blackford County shall "enjoy the rights and privileges" of an independent county. The act also appointed commissioners, and corrected a misprint that defined the southeast corner of the new county.
Over the next two years, a political "battle" continued over the location of the county seat. The tiny community of Hartford was repeatedly selected by the commissioners, but those decisions were challenged by individuals favoring Montpelier. While Licking Township (location of community of Hartford) was the most populous township in the county, the community of Montpelier was the county's oldest platted community. After a third and fourth act of the Indiana General Assembly, Hartford was finalized as the location of the county seat—and construction of a courthouse began. Because it was discovered that another community in Indiana was also named Hartford, Blackford County's Hartford was eventually renamed Hartford City.
During the next 25 years, the county grew slowly. Plans were made for roads and railroads, and swampland was drained. The first railroad line was authorized in 1849. The plan was for the Fort Wayne & Southern Railroad Company to connect the Indiana cities of Fort Wayne and Muncie—running north–south through the Blackford County communities of Montpelier and Hartford City. Although work constructing the railroad line began in the 1850s, it was not completed (by connecting Fort Wayne to Muncie) until 1870, and this delay caused it to be the second railroad to operate in Blackford County. By the time the railroad began operations, it was named Fort Wayne, Cincinnati & Louisville Railroad. The Lake Erie and Western Railroad acquired this railroad in 1890.
The first railroad to operate in Blackford County crossed somewhat east–west through the county's southern half. The railroad was named Union and Logansport Railroad Company by the time it entered Blackford County. This line was proposed in 1862, and completed to Hartford City in 1867—running through the Blackford County communities of Dunkirk, Crumley's Crossing, and Hartford City. The small community of Crumley's Crossing was renamed Converse, and two other communities (Millgrove and Renner) became established on this line. The railroad was eventually named Pittsburgh, Cincinnati and St. Louis Railroad. Other names for the railroad since that time include the Panhandle division of the Pennsylvania Railroad, Penn Central Railroad Company, Conrail, and Norfolk Southern Railway. A portion of this line is now abandoned, and the track has been removed between Converse and Hartford City, south of State Road 26.
In 1886, natural gas was discovered in two counties adjacent to Blackford County. The discoveries were in the small community of Eaton (south of Hartford City along railroad line) in Delaware County, and in the city of Portland in Jay County (east of Hartford City and Millgrove). The Hartford City Gas & Oil Company was formed in early 1887, and successfully drilled a natural gas well later in the year. In Montpelier, the Montpelier Gas & Oil Mining company was organized in the spring of 1887. While natural gas was found throughout Blackford County, crude oil was found mostly in the county's Harrison Township (somewhat between Montpelier and Mollie). Blackford County's first successful oil well, located just south of Montpelier, began producing during 1890. Montpelier was thought to be "the very heart of the greatest natural gas and oil field in the world". Oil was also found in parts of Washington Township, including a well that was thought to be "the most phenomenal well ever drilled in America". By 1896, Blackford County had 18 natural gas companies. These companies were headquartered in all four of the county's townships, including the communities of Hartford City, Montpelier, Roll, Dunkirk, Trenton (Priam Post Office), and Millgrove.
In June 1880, only 171 people held manufacturing jobs in Blackford County. The Indiana Gas Boom transformed the region, as manufacturers moved to the area to utilize the natural gas and railroad system. During 1901, Indiana state inspectors visited 21 manufacturing facilities in Blackford County, and these companies employed 1,346 people (compare to 171 two decades earlier). Since these inspections were in Hartford City and Montpelier only, additional manufacturing employees from the county's small communities (such as Millgrove's glass factory) could be added to the count of 1,346. The county's two largest employers were glass factories: American Window Glass plant number 3 and Sneath Glass Company. Hartford City's resources (low cost energy, two railroads, and workforce) were especially favored by glass factories, and a 1904 directory lists 10 of them.
In addition to an economic transformation, another byproduct of the gas boom was an upgrade of Blackford County's appearance. Many of the county's landmark buildings were constructed during the gas boom, including the current courthouse and surrounding buildings in Hartford City's Courthouse Square Historic District. The city's waterworks was also built during that period. Additional buildings include the Carnegie Library and historic Presbyterian Church. In Montpelier, many of the buildings in its Downtown Historic District were also constructed during the gas boom. Montpelier's historic Baptist Church and Montpelier's Carnegie Library were constructed in the early 1900s – near the end of the gas boom.
The Indiana Gas Boom gradually came to an end during the first decade of the 20th century. The end of the gas boom meant less prosperity for the county. The gas and oil workers left, some of the manufacturers moved, and the service industries were forced to close or cut back operations because of fewer customers. Adding to the county's problems, machines made the labor–intensive method originally used for producing window glass obsolete, causing many of the county's skilled glass workers at the large American Window Glass plant to lose their jobs. By 1932, the window glass plant of the county's former largest employer was closed. According to the United States Census, Blackford County's population peaked at 17,123 in 1900, and it still has not returned to that zenith over 100 years later.
The end of the gas boom was especially difficult for the smaller communities in the county, since the loss of a single business had more of an impact on undersized communities than it did for a town with many businesses. In the case of Millgrove, the community's major manufacturer (a glass factory) closed. For other communities, such as Mollie, the loss of the gas and oil workers meant that the local post office was a "waste of time", and consumer demand at the general store was significantly diminished.
Improvements to the automobile and highways, which coincided with the end of the gas boom, may have also contributed to the decline of the county's smaller communities. The automobile changed "business and shopping patterns at the expense of the small-town merchant." Small town residents began to drive to larger communities to purchase goods, because of the wider selection. The improved quality of automobiles and roads competed with passenger service on the railroads (and interurban lines), causing a decline in passenger traffic on the rails. Small towns associated with railroad stations suffered from the loss in traffic. In Blackford County, passenger service on the Lake Erie and Western Railroad line (owned by the Nickel Plate Road by that time) was discontinued in 1931, and the last interurban train ran on January 18, 1941.
Although the natural gas and oil workers left the area after the gas (and oil) boom, Montpelier's population eventually stabilized—and Hartford City's grew. Some of the manufacturers remained in the county's two largest cities because of a lack of better alternatives. Hartford City's Sneath Glass Company, a major employer, continued operations until the 1950s. Hartford City leaders attracted businesses such as Overhead Door (1923) and 3M (1955) to replace some of the companies that left the area. Overhead Door was a major employer in Hartford City for over 60 years. A major setback for the community involving Overhead Door occurred during the 1980s, although it began in the 1960s. During the 1960s, Overhead Door moved its headquarters from Hartford City to Dallas, Texas. Its Hartford City manufacturing plant continued to be a major employer until the 1980s, when Overhead Door cut back local operations. The Hartford City facility finally closed in 2000. The county lost another major Hartford City employer in 2011 when the Key Plastics plant closed, as 200 people lost their jobs.
Agriculture continues to be an important factor in the county's economy. Over 70 percent of Blackford County's land is occupied by soybean or corn fields. Additional crops and livestock are also raised. Good returns in agriculture are not always reflected in the economy of nearby towns, as industrial agriculture has reduced the number of workers it needs, and family farms have declined. Many small towns in the "Corn Belt", such as the communities in Blackford County, continue to decline in size and affluence.