It was designated a National Historic Landmark in 2012, as the site of Gonzalo Mendez et al v. Westminster School District of Orange County, et al, a major legal case in advancing the civil rights of Mexican-Americans, and a precursor to the landmark Brown v. Board of Education case.

[2] Before it was Downey Block, the northwest corner of Temple and Main that was eventually used for the 1910 and 1937 courthouse buildings was a slave market during the mid-19th century, after California had been incorporated into the Union.

In 1850, the California State Legislature signed into law the Act for the Government and Protection of Indians, which allowed for any indigenous Californian to be declared as a "vagrant" by white Americans and taken before a justice of the peace; those who did were subsequently sold at public auction into de facto slavery.

His work includes lodges in National Parks, over two dozen post offices, a number of federal courthouses, and the magnificent United States Mint in San Francisco.

The House Un-American Activities Committee met in the building in 1947 to gather information on Hollywood personalities suspected of Communist involvement.

[7] Other portions of the U.S. Court House remain in use by certain federal agencies, including the U.S. Attorney's office, and Probation and Pretrial Services.

[7] Located on a landscaped one-acre site bounded by Spring, Main, Temple and Aliso Streets in the Los Angeles Civic Center, the courthouse is a major example of Art Moderne architecture, characterized by its stepped rectangular massing and restrained use of exterior ornamentation.

Above a polished granite base, the seventeen-story steel-frame building is clad with a pale pink matte-glazed terra-cotta veneer.

Each of the five entrance doorways consists of a pair of bronze doors capped by a projecting curved hood bearing a stylized eagle.

These grilles are decorated with flowers and the seals of five U.S. Government departments: State, Treasury, War, Justice, and Post Office.

[5] The opposite elevation, which faces Main Street, is similar, but has an additional lower story due to the slope of the site, and three entry bays rather than five.

The other, titled The Young Lincoln, is by local art student James Lee Hansen; it won a Federal Works Agency competition [8] The Spring Street lobby, which originally accommodated the post office, is larger, with a rectangular plan, and has a higher ceiling than the Main Street lobby.