Alan Stephenson Boyd was born on July 10, 1922, in Jacksonville, Florida. During World War II, he served with an Army Troop Transport Command. After he returned from service, he attended the law school at the University of Virginia, earning his law degree in 1948.

Following graduation, he returned to Florida to practice law and was chosen to sit on a state commission exploring the development and regulation of transportation. President Eisenhower appointed Boyd in 1959 to the Civil Aeronautics Board (CAB). Boyd continued serving on the CAB during the Kennedy years and was tapped as its chairman. In that capacity, Boyd helped an ailing airline industry recover from disappointing profits and standardize its fare reductions.

Boyd was also responsible for approving government subsidies to help maintain less profitable airline routes between smaller cities. In 1965, President Johnson appointed him undersecretary of commerce for transportation. While serving in that capacity, Boyd headed a task force to study the maritime industry. Issued in 1965, the task force report suggested reducing the government's subsidy to the industry and as well as the number of restrictions the government placed upon it. The report led to conflict with the industry's labor leadership. Boyd was at the root of a second confrontation with labor when he issued statements denouncing "featherbedding" by the railroad firemen.

The Johnson administration wanted to unify over 35 different agencies dealing with transportation. Boyd was a part of the committee, which began lobbing for a cabinet-level Department of Transportation, or DOT, in September 1965. When Congress finally passed the bill creating the DOT, in October 1966, the secretary of transportation was given significantly less power than Johnson had intended, thought the Maritime Administration was brought under the auspices of the DOT.Nevertheless, Johnson appointed Boyd to be the nation's first secretary of transportation in November 1966. As secretary, Boyd worked on airport modernization, air traffic control requirements, and auto safety standards for driver education and alcoholism. He also helped acquire appropriations for Lady Bird Johnson's Highway Beautification Program. Boyd used his new control over interstate highway funds to give President Johnson's tax surcharge some power.

One of his biggest failures as secretary was his inability to revitalize passenger rail service. Boyd's period of service as secretary of transportation ended with the advent of the Nixon administration. At that point, Boyd became president of the Illinois Central Railroad. Controversy arose, however, when Boyd was accused of a conflict-of-interest, after news leaked that the DOT had given the Illinois Central $25.2 million in aid. Boyd was cleared of all charges following an investigation.