Hanover County was created on November 26, 1719, from the area of New Kent County called St. Paul's Parish. It was named for the Electorate of Hanover in Germany, because King George I of Great Britain was Elector of Hanover at the time.
Hanover County was the birthplace and home of noted American statesman Patrick Henry. He reportedly married Sarah Shelton in the parlor of Rural Plains, also known as Shelton House because of her family's residency. At the Hanover Courthouse, he argued the case of the Parson's Cause, attacking the Crown's attempt to set the salaries of clergy in the colony. The historic Hanover Courthouse is pictured in the county seal. Hanover County was also the birthplace of politician Henry Clay, author of the Missouri Compromise of 1820.
Hanover County at its closest point is only from the current city limits of Richmond. However, the Chickahominy River is located at this closest point, which is in the Mechanicsville area. Although the Union Army came within earshot of the bells of Richmond's churches during the 1862 Peninsula Campaign of the American Civil War, they learned that the river was a major obstacle. Union General George B. McClellan failed in the attempt to get all of his troops across it to overwhelm the smaller-sized Confederate forces defending Richmond. This failure to take Richmond could be said to have prolonged the War almost 3 more years. Hanover County was the site of a number of Civil War battles, including the Seven Days Battles of the Peninsula Campaign and Battle of Cold Harbor in 1864.
In 1953, Barksdale Theatre was founded at the historic Hanover Tavern, becoming the nation's first dinner theatre and Central Virginia's first professional theatre. Barksdale continues to produce live theatre at the Tavern, as well as at several locations in Richmond. It is recognized today as Central Virginia's leading professional theatre.
In January 2007, America's Promise named Hanover County as one of the top 100 communities for youth.