Before the arrival of European settlers, the area that would become Harlem (originally Haarlem) was inhabited by the Manhattans, a native tribe, who along with other Native Americans, most likely Lenape, occupied the area on a semi-nomadic basis. As many as several hundred farmed the Harlem flatlands. Between 1637 and 1639, a few settlements were established. The settlement of Harlem was formally incorporated in 1660 under the leadership of Peter Stuyvesant. During the American Revolution, the British burned Harlem to the ground. It took a long time to rebuild, as Harlem grew more slowly than the rest of Manhattan during the late 18th century. After the American Civil War, Harlem experienced an economic boom starting in 1868. The neighborhood continued to serve as a refuge for New Yorkers, but increasingly those coming north were poor and Jewish or Italian. The New York and Harlem Railroad, as well as the Interborough Rapid Transit and elevated railway lines, helped Harlem's economic growth, as they connected Harlem to lower and midtown Manhattan.