This series contains materials related to Brown's work as a representative of four different congressional districts in California during his time in office. Brown served areas of East Los Angeles in District 29 from 1963-1970, and parts of Riverside and San Bernardino Counties, also known as the Inland Empire, from 1973-1999 as a representative of the 38th, 36th, and 42nd Districts. These three districts contained many of the same areas of the Inland Empire, but due to statewide redistricting consisted of different borders and included some differing cities and constituents. Due to the similarities between districts and Congressman Brown's dedication to the region as a whole, Brown's office sometimes took on projects and developed relationships that affected the entire Inland Empire rather than just his district cities. As a result, some materials in the series document areas slightly outside of Brown's district, but were considered district materials as they were locally relevant to his constituents. The shared areas of Brown's districts also means many topics, organizations, and projects have files in multiple district subseries.

Materials in the series include events attended and given by Brown in his districts, files on district projects and local issues, and information on various organizations and services relevant to his constituents including city and county services, development projects, local schools and universities, district businesses, water resources, employment assistance, local military bases, and economic growth opportunities.