Modern pioneers began reclaiming Jackson Street's historic 400 block from destruction and converting it into one of the most ingratiating sectors of the city in the mid-1900s.
The entrance of Jackson Square was the home of the city's first bridge. The bridge was built in 1844. In September, 1972 the City's Board of Supervisors officially proclaimed the area bounded by Columbus Avenue on the west, a line midway between Broadway and Pacific on the north, Sansome on the east and Washington on the south an Historic District and designated 17 of its buildings as landmarks.
Landmarks of special interest on Jackson between Sansome and Montgomery are 400 Jackson, dating in part from 1859; 415-31 Jackson, built in 1853 and used by Domingo Ghiradelli as his chocolate works prior to moving it to the present Ghiradelli Square site in 1894; 441 Jackson, erected in 1861 on the hulls of two ships abandoned in the Gold Rush.