John D. Dingell, the longest-serving member of Congress in American history, and easily the most overpoweringly influential House chairman of this generation, is calling an end to his own era.

A complex and cunning Democrat who is in his 59th year of representing the Detroit area and who will turn 88 in July, Dingell announced Monday that he would retire at the end of the year rather than seek a 30th full term. The news floored the Capitol, where almost no one in the workaday population has known life without his presence.

“Presidents come and presidents go,” President Bill Clinton said in 2005 when the congressman celebrated half a century in office. “John Dingell goes on forever.”

Dingell earned the lasting nickname “Big John,” and the widespread expectation that his time in public life wasn’t near its end, thanks to much more than unmatched perseverance.

His imposing 6-foot-3 frame has become stooped in recent years, and he often moves through the Capitol on a motorized scooter with a faux vanity license plate of “The Dean” — the honorary title bestowed on the sitting House member with the longest tenure. But he had been talking in recent days about waging a comeback campaign to reclaim his party’s top seat on the Energy and Commerce Committee, where he exercised unequaled power as chairman for 16 years and was ranking Democrat for a dozen years more.

Although he was deposed from that post six years ago, and seemed unlikely to get it back, the successes he enjoyed in the previous three decades as a canny legislative playmaker, tenacious oversight inquisitor and vigorous turf warrior has rarely been rivaled in congressional history.

“One of the most influential legislators of all time,” President Barack Obama said in his tribute Monday.

The president noted Dingell’s central roles in writing the original Clean Air Act, the Safe Drinking Water Act and the Endangered Species Act, but paid special tribute to the most prominent cause they shared: medical insurance coverage for all. (Dingell presided over the House when it cleared the law creating Medicare in 1965 and sat next to Obama at the health care overhaul signing ceremony in 2010. He had proposed “single payer” universal coverage legislation in every Congress until that point, but professed himself satisfied with the measure enacted.)

From the outset of his Energy and Commerce chairmanship in 1981, Dingell was known as a legislative strategist and political tactician with the capacity to mold broad bipartisan coalitions to his will — although rarely without a fair amount of bruising. His style was to be collaborative in the early stages of legislative bargaining, then clamp down as inflexible once he’d declared his position was settled. Even his allies viewed him as uncommonly stubborn, vindictive and bullying for someone with so much guaranteed power — and with a self-confidence bordering on arrogance, to boot.

In short, his loud voice, heavy gavel and strong opinions made him a paragon of the domineering chairman just as that type of Old Bull leader was otherwise nearing extinction.

And he paired all that with a reputation for ruthless accretion of power, with much of the effort spent amassing and then protecting the broadest committee fiefdom any chairmen had enjoyed in the postwar era. In its heyday, Energy and Commerce had most if not all control over bills shaping energy, environmental, health, telecommunications, transportation, financial services and consumer protection policy.