Lawrence Sidney Eagleburger was born in Milwaukee, Wisconsin on August 1, 1930, and graduated from the University of Wisconsin (B.S.,1952). After college, Eagleburger enlisted in the U.S. Army, where he served as a first lieutenant, before returning to the University of Wisconsin and earning his M.A. in 1957. Later that year, Eagleburger joined the U.S. Foreign Service, working as a consul in Honduras and later as desk officer for Cuban affairs in the State Department's Bureau of Intelligence and Research. In 1961, he was assigned to the U.S. Embassy in Belgrade, Yugoslavia (1961-1965), returning later to serve as special assistant to presidential advisor Dean Acheson on Franco-NATO affairs (1965).During the Nixon administration, Eagleburger was an assistant to national security advisor Henry Kissinger (1969-1971). He subsequently served as advisor and chief of section for the U.S. Mission to NATO in Brussels, deputy assistant secretary of defense, acting assistant secretary for international security affairs, and deputy assistant to the President. When Kissinger was appointed secretary of state, Eagleburger became his executive assistant and, subsequently, deputy undersecretary for management. President Jimmy Carter named Eagleburger ambassador to Yugoslavia (1977-1980). Following his stint in Belgrade, President Ronald Reagan appointed Eagleburger assistant secretary of state for European affairs (1981). In 1982, Eagleburger was named undersecretary of state for political affairs, the third-ranking position in the State Department. President Bush named him deputy secretary of state in 1989.

When James A. Baker left the State Department to run Bush's reelection campaign, Eagleburger stepped in and became secretary of state for the remainder of the Bush presidency.