On Oct 3, 1965, Johnson signs the Immigration and Nationality Act (INA) of 1965, which amended the 1952 INA by including a provision stating: No person shall receive any preference or priority or be discriminated against in the issuance of an immigrant visa because of the person's race, sex, nationality, place of birth, or place of residence.
Timeline:
1924 - Coolidge signs Johnson-Reed Act
Prevents immigration from Asia and establishes a quotas system
1952 - Truman vetoes McCarran-Walter Act (veto overridden by Congress)
Eliminates Asian exclusion and establishes a preference system for desirable ethnic groups
1965 - Johnson signs Hart-Celler Act
Eliminates policy of limiting immigration based on national origin
Note: See https://immigrationhistory.org/timeline for a description of immigration laws before 1924
Resources:
Johnson-Reed Act: https://history.state.gov/milestones/1921-1936/immigration-act
McCarran-Walter Act: https://history.state.gov/milestones/1945-1952/immigration-act
Hart-Celler Act: https://history.house.gov/Historical-Highlights/1951-2000/Immigration-and-Nationality-Act-of-1965
Coolidge’s INA Comments: https://www.coolidgefoundation.org/blog/were-all-in-the-same-boat-now-coolidge-on-immigration
Truman’s INA Comments: https://www.trumanlibrary.gov/public/Immigration_TrumanVeto.pdf
Johnson’s INA Comments:http://www.lbjlibrary.org/lyndon-baines-johnson/timeline/lbj-on-immigration