A photograph of the Pioneer, a steam locomotive, which was built in Boston and put into service in San Francisco, ca. 1868.

The note on back of image reads: "Built in Boston and brought around Cape Horn to San Francisco in 1855, this locomotive was christened the ‘Elephant’ because of its size, and went to work grading San Francisco sand hills. In 1856 it was sold to the Sacramento Valley Railroad and rechristened the ‘C. K. Garrison.’ By a third christening in 1868, it became the "Pioneer" in recognition of its distinction of being the first locomotive used on a California railroad and probably the first on the Pacific coast.”