It had originally been the hope of Walter Brennan (and his family) that he would follow in the footsteps of his father, an engineer; but while still a student, he was bitten by the acting bug and was already at a crossroads when he graduated in 1915. Brennan had already worked in vaudeville when he enlisted at age 22 to serve in World War I. He served in an artillery unit and although he got through the war without being wounded, his exposure to poison gas ruined his vocal chords, leaving him with the high-pitched voice texture that made him a natural for old man roles while still in his thirties. His health all but broken by the experience, Brennan moved to California in the hope that the warm climate would help him and he lost most of what money he had when land values in the state collapsed in 1925. It was the need for cash that drove him to the gates of the studios that year, for which he worked as an extra and bit player.
The advent of the talkies served Brennan well, as he had been mimicking accents in childhood and could imitate a variety of different ethnicities on request. It was also during this period that, in an accident during a shoot, another actor (some stories claimed it was a mule) kicked him in the mouth and cost him his front teeth. Brennan was fitted for a set of false teeth that worked fine, and wearing them allowed him to play lean, lanky, virile supporting roles; but when he took them out, and the reedy, leathery voice kicked in with the altered look, Brennan became the old codger with which he would be identified in a significant number of his parts in the coming decades. He can be spotted in tiny, anonymous roles in a multitude of early-'30s movies, including King Kong (1933) (as a reporter) and one Three Stooges short. In 1935, however, he was fortunate enough to be cast in the supporting role of Jenkins in The Wedding Night. Directed by King Vidor and produced by Samuel Goldwyn, it was supposed to launch Anna Sten (its female lead) to stardom; but instead, it was Brennan who got noticed by the critics. He was put under contract with Goldwyn, and was back the same year as Old Atrocity in Barbary Coast. He continued doing bit parts, but after 1935, his films grew fewer in number and the parts much bigger. It was in the rustic drama Come and Get It (1936) that Brennan won his first Academy Award as Best Supporting Actor. Two years later, he won a second Best Supporting Actor Oscar for his performance in Kentucky (1938). That same year, he played major supporting roles in The Texans and The Buccaneer, and delighted younger audiences with his moving portrayal of Muff Potter, the man wrongfully accused of murder in Norman Taurog's The Adventures of Tom Sawyer. Brennan worked only in high-profile movies from then on, including The Story of Vernon and Irene Castle, Stanley and Livingston, and Goldwyn's They Shall Have Music, all in 1939. In 1940, he rejoined Gary Cooper in The Westerner, playing the part of a notoriously corrupt judge. Giving a beautifully understated performance that made the character seem sympathetic and tragic as much as dangerous and reprehensible, he won his third Best Supporting Actor award. There was no looking back now, as Brennan joined the front rank of leading character actors. His ethnic portrayals gradually tapered off as Brennan took on parts geared specifically for him. In Frank Capra's Meet John Doe and Howard Hawks' Sergeant York (both 1941), he played clear-thinking, key supporting players to leading men, while in Jean Renoir's Swamp Water (released that same year), he played another virtual leading role as a haunted man driven by demons that almost push him to murder. He played only in major movies from that point on, and always in important roles. Sam Wood used him in Goldwyn's The Pride of the Yankees (1942), Lewis Milestone cast him as a Russian villager in The North Star (1943), and he was in Goldwyn's production of The Princess and the Pirate (1944) as a comical half-wit who managed to hold his own working alongside Bob Hope. Brennan played the choice role of Ike Clanton in Ford's My Darling Clementine (1946) and reprised his portrayal of an outlaw clan leader in more comic fashion in Burt Kennedy's Support Your Local Sheriff some 23 years later.
He worked with Cooper again on Delmer Daves' Task Force (1949) and played prominent roles in John Sturges' Bad Day at Black Rock and Anthony Mann's The Far Country (both 1955). In 1959, the 64-year-old Brennan got one of the biggest roles of his career in Hawks' Rio Bravo, playing Stumpy, the game-legged jailhouse keeper who is backing up the besieged sheriff. By that time, Brennan had moved to television, starring in the CBS series The Real McCoys, which became a six-season hit built around his portrayal of the cantankerous family patriarch Amos McCoy. The series was such a hit that John Wayne's production company was persuaded to release a previously shelved film, William Wellman's Goodbye, My Lady (1956), about a boy, an old man (played by Brennan), and a dog, during the show's run. Although he had disputes with the network and stayed a season longer than he had wanted, Brennan also liked the spotlight. He even enjoyed a brief, successful career as a recording artist on the Columbia Records label during the 1960s. Following the cancellation of The Real McCoys, Brennan starred in the short-lived series The Tycoon, playing a cantankerous, independent-minded multimillionaire who refuses to behave the way his family or his company's board of directors think a 70-year-old should. By this time, Brennan had become one of the more successful actors in Hollywood, with a 12,000-acre ranch in Northern California that was run by his sons, among other property. He'd invested wisely and also owned a share of his first series. Always an ideological conservative, it was during this period that his political views began taking a sharp turn to the right in response to the strife he saw around him. During the '60s, he was convinced that the anti-war and civil rights movements were being run by overseas communists -- and said as much in interviews. He told reporters that he believed the civil rights movement, in particular, and the riots in places like Watts and Newark, and demonstrations in Birmingham, AL, were the result of perfectly content "Negroes" being stirred up by a handful of trouble-makers with an anti-American agenda. Those on the set of his last series, The Guns of Will Sonnett -- in which he played the surprisingly complex role of an ex-army scout trying to undo the damage caused by his being a mostly absentee father -- say that he cackled with delight upon learning of Martin Luther King Jr.'s assassination in 1968. Brennan later worked on the 1972 presidential campaign of reactionary right-wing California Congressman John Schmitz, a nominee of the American Party, whose campaign was predicated on the notion that the Republican Party under Richard Nixon had become too moderate. Mostly, though, Brennan was known to the public for his lovable, sometimes comical screen persona, and was still working as the '60s drew to a close, on made-for-TV movies such as The Over-the-Hill Gang, which reunited him with one of his favorite directors, Jean Yarbrough, and his old stablemate Chill Wills. Brennan died of emphysema in 1974 at the age of 80.