[3] He began a law firm with C. T. Ryland, and was joined after January 1851 by Peter H. Burnett, after he completed his term as the first Governor of California.

[7][8] In October 1869, Wallace ran against Lorenzo Sawyer and was elected as an associate justice of the California Supreme Court.

[16][17] On January 12, 1881, the California State Assembly chose Republican General John F. Miller of Napa to replace Newton Booth as U.S.

In 1882, Wallace was nominated by the Democratic Party and elected Assemblyman from the 13th district, holding a seat in the California State Assembly from January through March, 1883.

[20][21] In October 1886, Wallace was elected as a judge of the San Francisco County Superior Court, Department Six, for a six-year term.

[24][25][26] In 1899, Wallace was appointed to the San Francisco Police Commission by Mayor James D. Phelan, and held that position until 1903.

[1] In October 1875, Governor Romualdo Pacheco appointed Wallace a regent of the University of California.