As early as 1895, the Brooklyn Bridegrooms baseball team (see Dodger history) was nicknamed Brooklyn Trolley Dodgers, due to the numerous (and hazardous) trolley lines that criss-crossed Brooklyn at the time. In 1911, the Dodgers name was formally adopted by the team and, by the 1913 season, was shortened to Brooklyn Dodgers. In 1914, the team was renamed Brooklyn Robins, so named for its team manager, Wilbert Robinson. After Robinson retired in 1932, the team re-adopted its earlier name, Brooklyn Dodgers. They became the Los Angeles Dodgers upon the team's move to Los Angeles in 1958.
L.A. Video: History of the Dodgers