During the Second Seminole War in 1836, the U.S. Army established Camp Monroe as a staging area for unloading troops and supplies near the river, with a road that eventually became Mellonville Avenue connecting the camp to the river. The camp, enclosed by pickets on three sides and open to the river, held approximately 300 men, and in 1837 a long pier built at the end of the army road for receiving supplies became the Mellonville Pier. On February 8, 1837, Seminoles led by Emathla (King Phillip) and his son, Coacoochee, attacked in the Battle of Camp Monroe, killing Captain Charles Mellon and wounding fourteen men; three days later the camp was renamed Fort Mellon in his memory. In March 1837, a Capitulation Agreement was established between the U.S. Army and the Seminole people, and by May 2,500 Seminoles, including Osceola, peacefully camped near Fort Mellon under its terms, though hostilities did not completely end and Fort Reid was established to the south in 1840. The Armed Occupation Bill of 1842 brought settlers with grants of 160 acres to those who built a house and stayed five years, and most came from Georgia, Virginia, and the Carolinas. By 1851, Mellonville had grown up around Fort Mellon while the community to the south was called Fort Reid; Mellonville became the county seat of newly created Orange County in 1845 and held that role until 1856, when the seat moved to Orlando. As the fort disappeared, a river port developed, and Mellonville became the end of the line for settlers heading to South Florida after steamboat service was established between Mellonville and Jacksonville. It became the area's center of commercial activity, noted for its favorable location and productive orange groves, and by 1870 it was a prosperous town with many fine homes and a commercial district that controlled river traffic on the southern slope of Lake Monroe. After Henry Sanford bought land west of Mellonville to build a city, Mellonville incorporated in 1875 to preserve its identity, but the two towns remained separate only until 1883, when Mellonville was annexed into Sanford; Fort Reid was never incorporated, and much of that community was later lost when the Sanford Naval Air Station was built during World War II.