[4] The new city of Modesto (originally intended to be named for William Chapman Ralston) was founded in 1870 as the southern terminus of the Central Pacific Railroad, which bypassed the river towns by extending its line from Lathrop;[5] it soon became the most populous in the county, and assumed the county seat following a vote in 1871.

[6] A permanent building was constructed from 1872 to 1873 on land donated by the railroad; it was designed by Albert A. Bennett, with the ground floor entrance facing H Street.

[4] It was expanded in 1904, but the Modesto Herald noted "in comparison with the beautiful modern buildings that may be seen in other counties it is not especially attractive";[4] a grand jury's report in 1921 concluded a new courthouse was needed.

[7] Court operations moved to the Hall of Records in 1939 (at 1100 I St), and the old courthouse was demolished in 1958 to clear space for the current county offices.

[6][8][9] The current main court house (800 11th St) was dedicated on April 23, 1960, and criticized as a "large undistinguished box".