Shirley Temple: Child star who helped the US through the Depression and went to on serve two stints as an ambassador

Temple in 2006, when she was honoured by the US Screen Guild (AP)

America needed Shirley Temple. In the grip of the Depression, the dimpled, curly-haired child star sang, danced, sobbed and grinned her way into audiences' hearts. "As long as our country has Shirley Temple, we will be all right," President Roosevelt declared. "When the spirit of the people is lower than at any other time during this Depression, it is a splendid thing that for just 15 cents, an American can go to a movie and look at the smiling face of a baby and forget his troubles."

She was America's top box-office draw from 1935 to 1938, ahead of such grown-up stars as Clark Gable, Bing Crosby, Robert Taylor, Gary Cooper and Joan Crawford. In 1938, the year of Rebecca of Sunnybrook Farm, her income was the seventh-highest in the country, behind six industrialists. Along the way she saved 20th Century Fox from bankruptcy, but as she moved into her teens the cinema-going public didn't move with her, and her film career was over at 21. After dabbling in television, she forged a second career as a diplomat who was twice made an ambassador, once to Czechoslovakia as Communism fell.

She was born in Santa Monica in 1928. Her father, George, worked in a bank. Her mother, Gertrude, encouraged her to learn to dance, and she was enrolled in the Meglin Dance Studio in Los Angeles – also known as "Meglin's Wondrous Hollywood Kiddies" – when she was three (Judy Garland had also been a "Meglin Kiddie"). There, a talent-spotter from Educational Pictures saw her potential, and she was signed up for Baby Burlesks, a series of shorts in which young performers parodied grown-up films. In her best-selling 1988 autobiography Child Star Temple described them as "a cynical exploitation of our childish innocence that occasionally were racist or sexist."

She also made a series of two-reelers with Educational, Frolics of Youth, about the travails of a suburban family, and she was loaned to Tower Productions for her first feature film, Red-Haired Alibi (1932). But Educational Pictures went bankrupt in 1933, and Temple signed up with Fox Film Corporation. She had a few small parts before making her breakthrough in 1934 with Stand Up and Cheer! which portrayed a US president's attempts to lift the country's Depression-hit morale.

Fox executives were sold on Temple, and even before the film was released she was being pushed into the spotlight, though she was by no means the film's star. She stole the show with "Baby Take a Bow", the number she performed with James Dunn (who went on to win an Oscar in 1945 for A Tree Grows in Brooklyn). Her salary was raised to $1,250 a week, and her mother's to $150 as her coach and hairdresser. By the time she was loaned to Paramount a few months later for Little Miss Marker, a comedy-drama based on a Damon Runyon story, she was already America's most potent symbol of wholesome family entertainment.

At the end of 1934 came Bright Eyes, the first film built round the Temple persona: a cute, lovable orphan waif able to charm the gruffest of old men. As the film writer Charles Eckert observed, she played characters whose "capacity for love was indiscriminate, extending to pinched misers or to common hobos. It was a social, even a political force on a par with the idea of democracy or the constitution."

Bright Eyes launched "On the Good Ship Lollipop" and sent Temple's career soaring. Mothers dressed their daughters like her, and a line of dolls was launched that are still highly sought-after. She had a drink named after her, a sweet cocktail of ginger ale and grenadine topped with a maraschino cherry.

She followed up with a string of hit films, most of them with sentimental themes and musical subplots. Just as she had done in Bright Eyes, she often played a waif and stray, as in Curly Top (1935), in which she sang the hit song "Animal Crackers in My Soup," and Stowaway, in which she was befriended by Robert Young. She joined the great black dancer Bill "Bojangles" Robinson in two 1935 films with Civil War themes, The Little Colonel and The Littlest Rebel. Their tap dance up the steps in the former, coming at a time when interracial pairings were unheard of in Hollywood, became a landmark in the history of film dance. She won a special Academy Award in early 1935 for her "outstanding contribution to screen entertainment" the previous year.

Some of her pictures were remakes of silent films, such as Captain January (1936), in which she recreated the role originally played by the silent star Baby Peggy Montgomery in 1924. Poor Little Rich Girl (1936) and Rebecca of Sunnybrook Farm, (1938), done a generation earlier by Mary Pickford, were heavily rewritten for Temple, with showbiz plotlines added to give her opportunities to sing. In its review of Rebecca, Variety complained that a "more fitting title would be Rebecca of Radio City."

There was much more to Temple than curls and cute songs, however: she brought a professionalism well beyond her years to every film she made. She was "just absolutely marvellous, greatest in the world," recalled Allan Dwan, who directed her in Rebecca of Sunnybrook Farm, and Heidi the previous year. "You'd just tell her once and she'd remember the rest of her life. Whatever it was she was supposed to do, she'd do it ... And if one of the actors got stuck, she'd tell him what his line was – she knew it better than he did."

Not all critics fell for her. Reviewing Wee Willie Winkie for the magazine Night and Day, Graham Greene wrote: "Adult emotions of love and grief glissade across the mask of childhood, a childhood that is only skin-deep. It is clever, but it cannot last." His piece was held to be defamatory, and the magazine was bankrupted by the ensuing lawsuit.

Gertrude worked hard to keep her daughter from being spoiled by fame and was a constant presence on set. Shirley recalled years later that her mother had been furious when a director sent her off on an errand and then made Temple cry for a scene by frightening her. "She never again left me alone on a set," she said.

Thanks to Gertrude her young life was free of the scandals that plagued other child stars – parental feuds, drugs and alcohol – but Temple also spoke of a childhood she missed out on. She said she stopped believing in Father Christmas when she was six: "Mother took me to see him in a department store and he asked for my autograph."

There was little about her life that was normal. She had school lessons at the studio from tutors, was accompanied by bodyguards wherever she went and outside working hours tended to stay at home. Her life was insured for $795,000, with 20th-Century Fox the only beneficiary. On her eighth birthday – she was actually turning nine, but the studio needed her to stay young – she received more than 135,000 presents from around the world, including a baby kangaroo from Australia and a prize Jersey calf from schoolchildren in Oregon.

Maintaining that level of stardom proved difficult. Although Rebecca of Sunnybrook Farm was a hit in 1938, two other films the same year, Little Miss Broadway and Just Around the Corner, were panned by the critics, and the latter was the first Temple film to see a downturn in ticket sales. There was a proposal to have her play Dorothy in The Wizard of Oz, but that came to nothing as the head of 20th Century Fox, Darryl Zanuck, refused to lend out his greatest asset (Fox had merged with Twentieth Century Pictures in 1934). When The Little Princess in 1939 and The Blue Bird in 1940 didn't do well at the box office, Fox let her go. America didn't want its childhood idol to grow up, and neither did Fox.

In the mid-1940s (Getty)

Temple's parents bought up her contract and sent her to Westlake School for Girls, an exclusive school in Los Angeles. At the studio her bungalow was renovated, all traces of her removed, and the building reassigned as offices. She persisted for a few years before giving up altogether, however. Among her later films were The Bachelor and the Bobby-Soxer (later Bachelor Knight), in which she played a high-school girl with a crush on a suave older man played by Cary Grant, and That Hagen Girl with Ronald Reagan. Fort Apache (1948) was directed by John Ford, who had directed Wee Willie Winkie. In 1942 she had her first screen kiss, bestowed by another aging child star, Dickie Moore, in Miss Annie Rooney.

In 1945 Temple married an Army Air Corps private, John Agar, the brother of a classmate at Westlake. He took up acting and appeared with her in Fort Apache and another film, Adventure in Baltimore. They had a daughter, Susan, in 1948, but Temple filed for divorce the following year, and in 1950 she married a businessman, Charles Alden Black. They had two more children, Lori and Charles, their marriage lasting until Black's death in 2005.

There was a career of sorts on the small screen. In 1958 she hosted and narrated Shirley Temple's Storybook, an anthology series of fairy tale adaptations. She acted in three of the 16 hour-long episodes, and her son made his debut in the Christmas episode, "Mother Goose". Despite complaints of amateurish sets and poor special effects, it was reworked and released in colour in 1960 as The Shirley Temple Show. She continued to work on TV, making guest appearances on programmes such as The Red Skelton Show and Sing Along with Mitch. In 1965 she played a social worker in a sitcom pilot called Go Fight City Hall that wasn't picked up. Her screen career, big and small, was over.

Her interest in politics soon brought her back into the spotlight. She made an unsuccessful bid for Congress as a Republican in 1967, and when Richard Nixon became president he made her a member of the US delegation to the UN General Assembly. In the 1970s she was Ambassador to Ghana and also served as the first female US Chief of Protocol.

In 1972, she underwent surgery for breast cancer. She urged other women to have a check-up and told the world, "I have much more to accomplish before I am through."

She had a second ambassadorial stint, in Czechoslovakia during the administration of the first President Bush. A few months after she arrived in Prague in 1989, communist rule was overthrown. "My main job initially was human rights, trying to keep people like Vaclav Havel out of jail," she recalled in 1999. Within months she was accompanying the former dissident playwright when he came to Washington as his country's new president.

She considered her showbiz background an asset to her political career. "Politicians are actors too, don't you think?" she once said. "Usually if you like people and you're outgoing, not a shy little thing, you can do pretty well in politics." In 2006 as she was honoured by the Screen Actors Guild. "I have one piece of advice for those of you who want to receive the lifetime achievement award," she told the assembled gathering. "Start early."

Shirley June Temple, actress and diplomat: born Santa Monica 23 April 1928; married 1945 John Agar (divorced 1950; one daughter), 1950 Charles Alden Black (died 2005; one son, one daughter); died 10 February 2014.