Mercersburg is a borough in Franklin County that is 72 miles (116 km) southwest of Harrisburg. As of the 2020 census, Mercersburg had a population of 1,507. The land currently known as Mercersburg was previously territory of the Massawomeck people who were part of the Iroquois Nation.

Due to its location in a rural area, it had a relatively large percentage of African-American workers who had been enslaved from the Revolution. It was called “Black Town” in the early 19th century before incorporation under its current name. Refugee African Americans escaping from slavery in the South also settled here, and the area was known as “Little Africa”.

Mercersburg was platted in 1780. The borough was named after Hugh Mercer, a general and hero in the American Revolutionary War. A post office has been in operation at Mercersburg since 1812.

Located near the southern border of Pennsylvania, the rural community became a place of refuge during the antebellum years for escaped African Americans who had been enslaved in the South. Some came to the area via the Underground Railroad. After the American Revolution, Pennsylvania had abolished slavery. In this area were communities of free African Americans who had worked in agriculture. It was relatively easy for refugees to join their communities after passing over the border of Maryland. In later years, black people moved away from here as they were at risk from slavecatchers, especially after passage of the Fugitive Slave Act in 1850, which had more stringent rules against free states. Many African Americans moved to Philadelphia, which had a large and free black community, which helped new arrivals get settled.

The Mercersburg Historic District, Lane House, and Mercersburg Academy are listed on the National Register of Historic Places.

On September 26, 2003, this corner property was destroyed by fire exposing this log house built in 1791-1792 by Archibald Irwin. Irwin’s granddaughter Jane married William Henry Harrison, Jr., and served as First Lady when her father-in-law, William Henry Harrison, Sr., was elected 9th President of the United States. Irwin’s granddaughter Elizabeth married John Scott Harrison and became the mother of Benjamin Harrison, who served as 23rd President of the United States.

The Mercersburg Fountain is a beloved historical icon, originally placed in Center Square (The Diamond) in 1916. In 1915, the Woman’s Club of Mercersburg (now the Women’s Club) successfully raised money to install a fountain instead of a grass plot. The fountain stood in the Square until it was removed in 1959. After being lost for decades, it was purchased from an antique collector in 1991, restored, and rededicated to the Borough in 1994, finding a new home on North Fayette Street.