The Teamsters Union was never affiliated with the CIO, as indicated in an article yesterday on the union's relations with the Republican Party. It was once a member of the AFL and the AFL-CIO until expelled by the AFL-CIO in 1957.

Since it first endorsed Richard M. Nixon's 1960 presidential campaign, the Teamsters union has had an increasingly close relationship with Republican administrations. It was the only major union to endorse Ronald Reagan in 1980 and 1984.

The Teamsters-GOP tie provoked questions on Capitol Hill yesterday after the Justice Department confirmed that it had dropped a criminal investigation of Teamsters President Jackie Presser, although its own prosecutors in Cleveland had recommended indicting him. The Justice Department insisted yesterday that politics had nothing to do with its decision.

Presser was a member of the Reagan administration transition team after the 1980 election. Reagan made a major campaign speech at the Teamsters' convention in Columbus, Ohio, in the 1980 campaign. Reagan also was a luncheon guest of Presser and his father, William, a Teamsters official who had been convicted of destroying subpoenaed records and contempt of Congress.

Attorney General Edwin Meese III was a defender of the Teamsters and Presser before and after Reagan entered the White House. Apparently in return for the union's support, the administration watered down its plans for deregulating the trucking industry in Reagan's first term.

Until the 1950s, the Teamsters had been one of the most progressive unions in the old CIO. Franklin D. Roosevelt's famous "Little Dog Fala" speech was at a Teamsters meeting in Constitution Hall in 1944. But the pursuit of Teamsters presidents Dave Beck and James R. Hoffa by Democratic-controlled congressional committees in the 1950s made the union susceptible to Republican courtship and it endorsed Nixon in 1960.

The union endorsed Democrats Lyndon B. Johnson in 1964 and Hubert H. Humphrey in 1968, but Nixon wooed the leadership intensely for its endorsement in 1972. Nixon's courtship of the Teamsters began in December, 1971, when he commuted the sentence of Hoffa, the former Teamsters president, who then had served nearly five years in a federal minimum security prison for jury tampering and mail fraud.

The commutation was conditioned on Hoffa's commitment to refrain from attempting any "direct or indirect management of any labor organization" until 1980. The move, engineered by then-White House aide Charles W. Colson, who became the Teamsters' attorney a little more than a year later, was widely interpreted as an attempt to secure the position -- and good will -- of Hoffa's successor, Frank Fitzsimmons, by cutting Hoffa out of the picture.

Fitzsimmons was praised by Nixon administration officials as "the only Republican labor leader" and was a social visitor at the White House. He in turn refrained from joining other labor leaders in criticizing Nixon's wage-price freeze and other economic policies and hosted Nixon at a Teamsters executive committee meeting in Miami Beach.

In 1972, the administration dropped emergency legislation to combat transportation strikes and denied charges that it was part of a deal for Teamsters support.

The Nixon courtship of the Teamsters was not always a smooth one. In 1972, Colson leaned on the union to raise money for Nixon by hinting that the administration might lift the ban on Hoffa's union activities that had been the condition of his clemency. Common Cause, the citizens' lobbying organization, subsequently quoted Hoffa as saying that the Teamsters raised about $300,000 for Nixon.

Before the 1980 election, AFL-CIO officials had hoped to negotiate a merger of the Teamsters into the federation. The deal fell apart, federation officials say, when it became apparent that Reagan would be the GOP presidential nominee and Teamster officials decided they could deal with him directly.

"Their main concern isn't with issues or ideology," one AFL-CIO official said. "It's who controls the Justice Department."