Three years after Texas achieved independence, John Neely Bryan surveyed the area around present-day Dallas. In 1839, accompanied by his dog and a Cherokee he called Ned, he planted a stake in the ground on a bluff located near three forks of the Trinity River and left. Two years later, in 1841, he returned to establish a permanent settlement named Dallas. The origin of the name is uncertain. The official historical marker states it was named after Vice President George M. Dallas of Philadelphia, Pennsylvania. However, this is disputed. Other potential theories for the origin include his brother, Commodore Alexander James Dallas, as well as brothers Walter R. Dallas or James R. Dallas. A further theory gives the origin as the village of Dallas, Moray, Scotland, similar to the way Houston, Texas was named after Sam Houston whose ancestors came from the Scottish village of Houston, Renfrewshire. The Republic of Texas was annexed by the United States in 1845 and Dallas County was established the following year. Dallas was formally incorporated as a city on February 2, 1856.