Mr. Long sits at the bar at Hawk 'n' Dove in 2003. (Susan Biddle/The Washington Post)

Stuart J. Long, a lawyer turned saloon­keeper who co-founded the Hawk ‘n’ Dove tavern on Capitol Hill in 1967, its name a reflection of the soul-searing national debate over the U.S. waging of war in Vietnam, died July 29 at his home in Washington. He was 75.

The cause was cancer, said his son, James S. Long.

Mr. Long ran his tavern for 44 years until “The Hawk,” as it was known in its neighborhood, closed in 2011 when Mr. Long lost his lease. It reopened two years later under new management but without its gritty decor or the persona of its eponymous original patrons.

Over the years, Mr. Long also ran other taverns on Capitol Hill and elsewhere — Jenkins Hill, Duddington’s, Yolanda’s Al Campidoglio. He was among the first white businessmen to become major financial backers of Marion Barry for public office. He developed real estate on Capitol Hill, where he grew up; had a small legal practice; and was a prominent fundraiser and supporter for his high school alma mater, Gonzaga College High School.

But the reputation he cherished, and the one by which he was best known, was that of the barkeep of the Hawk ‘n’ Dove. As an upcoming young politician, Barry drank there. So did Supreme Court Justice William O. Douglas, House Speaker Thomas P. “Tip” O’Neill Jr. (D-Mass.), Rep. Bella Abzug (D-N.Y.) and thousands of congressional staffers, lobbyists, tourists and neighbors.

“I was the dove of the Hawk and Dove,” Mr. Long told former Washington Post reporter Megan Rosenfeld in a 2011 interview for a Capitol Hill history project. The bar opened at a time of turbulence and passion when millions of Americans were choosing sides — hawks or doves — on Vietnam, and were willing and ready to fight about it. The Hawk ‘n’ Dove bar was conceived as a place where disagreements could be settled peaceably.

Mr. Long’s business partner, Michael Lange, was the hawk, Mr. Long said.

“Did he go to Vietnam?” Rosenfeld asked.

“No,” said Mr. Long. “Most hawks don’t go to Vietnam, and they don’t send their kids either.”

Stuart James Long was born in Columbus, Ohio, on Jan. 21, 1942, and moved to the Washington area a year later. He was one of eight children. His father was a government social worker who helped establish an office of aging in what now is the Department of Health and Human Services. His mother bought, rehabilitated and sold houses in Washington neighborhoods including Capitol Hill.

After Gonzaga high school, Mr. Long enrolled at the College of the Holy Cross in Worcester, Mass., where he graduated in 1964. Years later, he would tell friends that he talked his way into George Washington University’s law school by telling the dean of admissions that he was about to be drafted into the Army and sent to Vietnam, from where, as likely as not, he would return in a body bag. The school took him in, and he received a law degree in 1967.

He took a job at the Library of Congress, within a stone’s throw of a collection of bars and restaurants in the 300 block of Pennsylvania Avenue SE. Within a few months he spied a vacant rental establishment that seemed suitable for a tavern, which at that time seemed to offer a livelier career than practicing law. It became the Hawk ‘n’ Dove.

He did not forsake the law entirely. Over the years he represented bars, taverns, restaurants and other small businesses periodically. He was vice chairman of the D.C. Armory Board from 1979 to 1991.

At Gonzaga, the gate to the school on North Capitol Street is the Stuart J. Long Class of 1960 Gate, in recognition of a variety of projects he undertook. In a letter to alumni, Gonzaga’s president, the Rev. Stephen W. Planning, wrote that Mr. Long’s friends “in high and low places” helped bring about much of what he did.

“He was the consummate everyman — as close and comfortable with politicians and decision-makers as he was with the busboy or bartender at the Hawk & Dove.”

Mr. Long’s survivors include his wife since 1982, Cherie McGuire Long of Washington; two children, James S. Long of New York City and Dr. Jessica McGuire Long of Washington; and two grandchildren.

Mr. Long liked to recall that 1967 — when he graduated from law school and opened the Hawk ‘n’ Dove — was the year when he “passed one bar and opened another.”