She was born in Pawtucket, Rhode Island, in 1900. As a child, she loved the early movies and she and her brother - allowed to go on Saturdays - would sit through the programmes twice. She was particularly impressed by the Biograph films, directed by D.W. Griffith. "In those days," she told a researcher, Susan McConachy, "they didn't have names for the people - Mae Marsh, Lillian Gish - but we made up names for them. Later on, I had the privilege of working with Mae Marsh and we became very close friends."
Her mother died when Ruth was 11, and she and her sister were placed in St Mary's Seminary on Narragansett Bay. At 15, Ruth and her sister moved to California to live with an aunt who had been a stage actress. She made her debut at the old Edison company, as an extra. She visited the Universal company, was quickly hired by Henry MacRae and by 1917 had risen to become one of their most valuable leading ladies, playing opposite some of the most popular leading men of the time.
The studio survived on its westerns; it employed authentic cowboys who found pictures paid better than ranching. Clifford was taught riding and shooting by these men - experiences which came in useful years later when she worked with John Ford on films like She Wore a Yellow Ribbon, Wagonmaster and The Searchers. (Ford liked her because she played bridge.)
At Universal, she became the favourite actress of the director Rupert Julian - who later directed the Lon Chaney version of The Phantom of the Opera (1925). "I worked with him for two years. He wouldn't let me work with any other director, which was considered a privilege." Julian - real name Percival Hayes - came from New Zealand. "He was very dignified and looked extremely severe. He wore a stunning little moustache, and was always beautifully groomed."
Oddly enough, he prided himself on his resemblance to the Kaiser. Julian directed Clifford in her most notorious film, The Kaiser, the Beast of Berlin (1918), with himself in the lead. Audiences became so worked up they threw things at the screen and when a German soldier - about to rape Clifford - is strangled, huge cheers went up. The picture's success brought Universal back from the brink of bankruptcy.
In 1919, while most of the East Coast studios were packing up and moving west, Clifford went in the opposite direction, and made pictures in New York for Charles Frohman and for David O. Selznick's father Lewis. Locations for The Peak of Gold were shot in Puerto Rico.
In 1923, she played in a Graustark story, Jerome Storm's Truxton King, opposite John Gilbert, soon to be the most romantic star of his generation. "My favourite leading man," she said. "We were working together and playing love scenes. I enjoyed kissing him but when he took me out I wouldn't let him kiss me goodnight! Isn't that silly? I guess I was a strange kid . . ."
One of her finest roles fortunately still survives - albeit in only one American archive. Clarence Brown, later responsible for some of Garbo's best pictures like Flesh and the Devil (1926) and Anna Karenina (1935), directed Butterfly in 1924. Clifford played Hilary Collier, who sacrifices her own career for the musical education of her talented young sister (Laura la Plante).
Silent film actresses have an unfair reputation for overacting in emotional scenes; Brown taught her never to go too far. "Do not cry," he advised her. "The audience will think it's self-pity. Keep a stone in your throat - swallow hard - but don't shed a tear." Hilary is deeply in love with an older man. When her sister bursts into the kitchen to tell her that he has proposed to her, Ruth Clifford responds with great stillness - and the scene is profoundly moving.
At the opening-night party, Brown confessed to her that he had tried hard to cast the role with a more famous star, but was glad he hadn't. "Then it was my turn to cry!" she said. "When you're young and haven't had experience in life, you depend on a good director - and an inspiration like that."
A more celebrated production came out the same year - Abraham Lincoln, Clifford's favourite of all her films. It was the pipe-dream of two youngsters who wanted to break into pictures with a bang. Al and Ray Rockett hired the great Frances Marion to write the script and Phil Rosen to direct. Alas, only two reels survive, and while the picture looks impressive, Clifford's role of Ann Rutledge is cut to the bone. The film won critical plaudits, but like so many high-minded Hollywood productions it was a financial flop.
In 1924, Clifford married James Cornelius, a real-estate agent who would develop much of Beverly Hills. They took a cruise to Hawaii for their honeymoon.
"Fortunately, marriage has proved beneficial to my career," Ruth told a journalist in 1925, "though, if it hadn't, the career could go hang itself." She turned down an offer to do a picture with Valentino because she and her husband had planned a fishing trip to their second home at June Lake. "I took my work too seriously, because I had so little else. I never had any fun. I didn't know how." Her marriage, she said, changed all that. And to her surprise, her fan mail increased. She and Cornelius had one son, James Cornelius Jnr.
Although her mother came from Manchester, Ruth Clifford was proud of her Irish background and, when an Abbey Players tour reached Los Angeles, she became a member of the company. Her career continued into television - she played in many episodes of Highway Patrol in the 1950s. On the screen, she worked with Spencer Tracy in Ford's The Last Hurrah (1958), with Gregory Peck in The Keys of the Kingdom (1944) and The Man in the Gray Flannel Suit (1956).
In the Seventies she was appearing in commercials - some for British television. In the late 1980s, she appeared in a documentary on Irish cinema and Irish stars for Ulster TV, A Seat among the Stars. She lived in Sherman Oaks outside Los Angeles until 1987, when she moved to the Motion Picture Home in Woodland Hills where she died.
"She was a remarkable person," said her friend the film historian Anthony Slide. "She disliked being interviewed. Sit her at dinner and she would regale you with stories, but put a tape recorder in front of her and she would clam up. Yet she enjoyed life so much - and was never stuck in the past. She was very well off and even in her nineties she loved to go on cruises to places like Hawaii, dancing into the small hours."
Ruth Clifford, actress: born Pawtucket, Rhode Island 17 February 1900; married 1924 James Cornelius (one son deceased); died Woodland Hills, California 30 November 1998.