Adam attended Townsend High School and graduated in January, 1925. His father insisted that he attend the City College of New York. The first semester, he failed three classes. The second semester, Adam failed every class and flunked out of school. His father arranged for Adam's admission in Colgate University. He graduated from Colgate, on June 9, 1930.

In 1930, Powell decided to succeed his father and was appointed the assistant minister and business manager of Abyssinia Church. He made use of his influential post by becoming active in various social and politics issues. During the Great Depression, Powell was the head of the relief program that gave out food and clothing to the needy. However, there was a limit to how much money members could contribute. The relief program was cut. In 1933, under the administration of a new president, Franklin Delano Roosevelt, the government began providing direct relief to the unemployed. Roosevelt also instituted a series of programs, called the "New Deal," to restore the nation's economy.

One evening in early 1933, five Harlem doctors called Powell. They were barred from practicing at Harlem Hospital, because they were black. Powell formed a committee to deal with Harlem Hospital. He staged a mass meeting and led a picket line. He then called for a demonstration on the steps of City Hall. The Board of Estimate agreed to investigate conditions at the hospital, and over the next few years the situation slowly improved. He got married to Isabel Washington that same year.

On February 12, 1938, 2,000 people crowded into the Abyssinian Baptist Church and heard Powell proclaim the formation of the Greater New York Coordinating Committee on Employment. The new organization aimed to use persuasion, pickets, and boycotts against employers who discriminated against blacks. Powell's organization was very successful. They first attacked the Consolidated Edison Company, then New York Bell Telephone Company. He also made white-owned businesses along 125th Street give in to some demands and promised at least one-third for their salespeople would be black.

In early 1941, after Powell was encouraged by Wendell Willkie's, he ran for City Council and won. He won an overwhelming number of the votes, winning 90 percent of the eligible votes. On January 1, 1942, Powell took oath of office and assumed a place on the city council. Even though Powell did not influence his fellow councilmen; they rejected every measure he proposed, he disrupted the normal flow of political business and called attention to injustices.

In 1943, Powell found that the City Council wasn't helping the Harlem community and in 1944, he ran for Congress and won. He caused much disruption among the other congressmen. In June 4, 1946, Powell proposed an amendment to a bill providing federal fund for free lunches for school children. His amendment barred states from excluding black children from the program. Powell's amendment was passed.

In 1952, Powell was investigated by the US. Department of Justice and the Internal Revenue Service. He paid $1,193 to cover his back taxes. Powell was brought before a grand jury by the Justice Department, on May 8, 1958. He was indicted for tax evasion. Powell retained his defense and the trial finally convened on March 18, 1960. After 26 hours of deliberation, Powell was acquitted of all charges.

A House committee headed by Congressman Wayne Hays of Ohio began an investigating Powell. On August 1, 1966, private investigators discovered Powell had charged scores of airline tickets to the account of his office staff. In 1967, Powell was stripped of his congressional seat after testifying before the investigative committee. On April 11, 1967, a special election was held to fill Powell's vacant seat, and Powell won 28,000 of the votes. He was re-elected by the voters, but he failed to show up in Congress.

After his defeat to State Assemblyman Charles Rangel, in 1970, Powell went to the Bahamas. He died on April 4, 1972, after an emergency operation in Miami.