3620769 James W Marshall, American sawmill operator whose discovery of gold at Coloma, California, in 1848 sparked the California Gold Rush (b/w photo) by American Photographer (19th century) (after); Private Collection; (add.info.: James W Marshall (1810-1885), American sawmill operator whose discovery of gold at Coloma, California, in 1848 sparked the California Gold Rush. Postcard, early 20th century.); by Look and Learn.