The history of Theresa begins with the Native Americans cultures who lived in the area as early as 841 B.C.. The first of the Native tribes to inhabit the town of Theresa was a group called the Meadowood Phase, who were early Woodland Indians according to the categorization of Dr.William A. Ritchie. This tribe is believed to be part of the early Adena culture and subsided on hunting and gathering. Evidence of the tribe existing in the area was found at Muskalonge and Red Lakes with finds of weapon points, nets, sinkers, and other various tools from needles to a beaver tooth wood scrapper. The Iroquois also used Theresa and the surrounding area as a hunting and fishing ground. Evidence supports that at one point the Iroquois had villages in the surrounding area and used the waterways of Theresa for trade and travel.
The first Europeans to stay in the town were not settlers, but were smugglers who used the water ways for their personal gain. The Indian River was a highway for trade and boat traffic, the only problem was the high falls. The falls made it necessary for the smugglers to carry their stolen merchandise from the upper to lower level, which required the use of two flat bottom boats.The boats the smugglers used were left behind and the early pioneers found and used the boats in the early settlement of the town.
The settling of Theresa begins January 4, 1800, when James LeRay bought of land from the Antwerp Land Company.  LeRay then subdivided the land for the purposes of settlement and development. By 1810-11 LeRay had early mills erected at the falls and brought cattle to graze, but settlement was stunted by the 1812 war.  After the war, development continued and in 1814,LeRay had a bridge built across the river and a year later a dam and mill were built just under the bridge. In 1817, the Shurtliff and the Ball families were the first to purchase lots in the town. A year previous to this President Monroe had the Military Road built for frontier protection that connected Theresa and most of the surrounding towns, which helped lead to more settlers coming to the North Country. Following the building of the road the first taverns were built at West Corners and Chaufty's Corners. LeRay had a gristmill and a tavern built to stimulate the sale of land. 
The improvements made by LeRay and others did much to stimulate the growth of the town. Over the next few years new businesses started to arrive. Within two years of the improvements made by LeRay,Theresa had its first blacksmith shop, brick maker, merchant, and physician. The first school house was built on Sand Hill in 1821. The school was used for a meeting hall more than a school and a few of the denominations of Christianity used it for a temporary church. The first cemetery was a piece of land donated and laid out by LeRay. The first mail route was a weekly mail delivered on horse back beginning some time in the 1820s. In 1831, a tri-weekly mail run was established. Eighteen years later the first telegraph office was set up mostly through the efforts of David Berup.
In 1841, the town of Theresa was organized into a separate township from the town of Alexandria, which it had been previously part of. The village of Theresa was not incorporated until 1871. In 1859, the first of Theresa's great fires took place. The fire destroyed two houses (one was the first house built in Theresa), three saw-mills, one wood working shop, one iron-working machine shop, and a gristmill. The bridge was also destroyed. Despite the fire in 1859, the town of Theresa was one of the most popular manufacturing and trading hubs in the North Country, even without a railway. The first railway to run through Theresa was the Black River and Morristown railroad in 1872. In the 1880s, Theresa continued its growth with a population increase of around 1200 people and with this new and higher population the businesses grew larger. By this time ordinary precautions were taken to prevent disaster but nothing was being done to guard against fire. In 1890, the second of the great fires took place. This fire swept through the business district of the town, destroying almost every business in Theresa. The total loss of property was 150,000 dollars with only about 100,000 in insurance. The fire destroyed 40 buildings, but this was somewhat good because it led to the building of more modern and attractive buildings. The fire also gave cause to build a town hall with businesses in the bottom and the upper floor being used for meetings and entertainment. The revenue from the businesses provided enough money for the town to build a village and fire hall and a fire department with some of the best equipment of the day.
In later years the town started to focus on the infrastructure, political, and recreational needs. In 1896, the Theresa Town Board appointed William Cheeseman the first attendance officer for schools outside the village because of the education laws of 1894. The first library in Theresa was created in 1900. The Town Board rented some lower rooms in the town hall to the Theresa Library Association for one dollar a year. In 1901 the town ordered the building of a iron bridge at Hanson Crossing to replace the failing bridge at the site. Theresa established the Board of Town Fire Commissioners in 1931 and established the Town Fire District, which encompassed the entire town. Six years later the first U.S. Standard Voting Machines were purchased for the town and the election districts redrawn. As of 1980, both the voting machines and the districts were still being used by the town. In 1975, Theresa received a grant from the E.J. Noble Foundation for a little less than $31,000 and was the first town in the state to receive such a grant. Then in 1976, a skating rink and warming house was built using funds from the Comprehensive Employment Training Act, Theresa Rotary Club, and the Village and Town of Theresa. Two years later purchased of land to construct a park which would contain the skating rink and then include a tennis and basketball court and other "unforeseen" facilities.