The area was once part of the Abenaki Indian territory called Rockemeka, meaning “great corn place”. It would be granted by the General Court of Massachusetts in 1771 as Port Royal, awarded to heirs of veterans who served in the campaign against the Acadian capital of Port Royal in 1710. It was settled in 1786, then incorporated in 1795 as Livermore after Deacon Elijah Livermore, one of the first English settlers. The county line, determined by the Androscoggin River, divided the town. West of the river was Oxford County, and east was Kennebec County. Consequently, East Livermore (which encompassed a quarter of the original Port Royal grant) was set off and incorporated on March 1, 1844. It became part of Androscoggin County on March 31, 1854. On March 15, 1929, East Livermore was renamed Livermore Falls.

In the early 19th century, the region was predominantly farmland, with apple orchards and dairies supplying markets at Boston and Portland. It was noted for fine cattle. As the century progressed, gristmills, sawmills, logging and lumber became important industries, operated by water power from falls that drop 14 feet. With the arrival of the Androscoggin Railroad in 1852, Livermore Falls developed as a small mill town. Shoe factories and paper mills were established, including the Umbagog Pulp Company started by Hugh J. Chisholm. In 1897, the Third Bridge was built across the Androscoggin. It measured 800 feet in length, at that time the longest single-span bridge in New England.