Seattle was incorporated by the Washington Territorial Legislature on December 2, 1869, and Atkins was appointed its first mayor. He was elected to the position outright on July 11, 1870, defeating Henry Yesler by sixteen votes, and served until July 1871.[2][3] He remained involved in civic affairs after his mayoral tenure,[2] later serving as sheriff of King County and as a regent of the Territorial University.[1][4] He died in 1885 and was buried at Lake View Cemetery in Seattle.[1]