In the American Civil War, the islanders supported the Union despite being located in a seceded state, and the war touched Chincoteague only lightly. Oysters became a major industry in the postwar years. Chincoteague's relative isolation ended in 1876 with the arrival of the railroad at Franklin City, Virginia, across Chincoteague Bay from the island, and the initiation of a dedicated steamboat service between the two settlements. Nevertheless, contemporary visitors found Chincoteague primitive. Part of the island was incorporated as the Town of Chincoteague within Accomack County in 1908; the municipality annexed the remainder of the island in 1989. Road traffic could reach the island with the completion of a causeway in 1922. Two devastating fires in that decade caused the establishment of the Chincoteague Fire Department in 1925; the new volunteer company took over the traditional pony penning, and soon had ponies from nearby Assateague Island swim the narrow channel between the two islands as part of that roundup. The carnival, pony swim, and subsequent auction constitute a highlight of the town's calendar, attracting tens of thousands to the island.
