Born in Everett, Washington, to Norwegian immigrants, Jackson practiced law in Everett after graduating from the University of Washington School of Law. He won election to Congress in 1940 and joined the Senate in 1953 after defeating incumbent Republican Senator Harry P. Cain. Jackson supported the major civil rights of the 1960s and authored the National Environmental Policy Act, which helped establish the principle of publicly analyzing environmental impacts. He co-sponsored the Jackson–Vanik amendment, which denied normal trade relations to countries with restrictive emigration policies.