During the depths of the Great Depression in the 1930s, Shirley Temple was so transcendent a star that her admirers stretched from Main Street to the White House. She began her movie career as a curly-haired moppet of 4 and embodied plucky good cheer and an effervescent can-do American spirit.

Recognizable for her dimpled cheeks, bright smile and precocious professionalism as a singer, dancer and comedienne, Miss Temple was the top box-office attraction in the United States from 1935 to 1938.

“When the spirit of the people is lower than at any other time during this Depression,” President Franklin D. Roosevelt once said, “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.”

After dancing and singing her way through dozens of movies as the most famous little girl in the world, Miss Temple later became known as Shirley Temple Black during a second career as a U.S. ambassador. She died Feb. 10 at her home in Woodside, Calif. She was 85.

Her death was announced by her publicist, Cheryl Kagan. The cause was not disclosed.

Her movies were classics of pre-World War II cinema, and in 1999, the American Film Institute included Miss Temple on its list of the 50 greatest screen legends. She was a Kennedy Center Honors recipient in 1998.

In 1938 — the year one of her best-regarded films, “Rebecca of Sunnybrook Farm,” was released — the 10-year-old Miss Temple had the seventh-highest income in the country.

But fame made it impossible for her to lead a normal life. She was tutored at the studio and accompanied everywhere by bodyguards. She was not allowed to swim for fear of damaging the curls her mother set in her hair each night. She was kept apart from other children, to prevent her from catching their illnesses.

After she stopped making movies in 1949, she served as White House chief of protocol, a delegate to the United Nations and an ambassador to Ghana and Czechoslovakia.

“I’ve led three lives: the acting part, wife and mother — which is a career — and international relations,” she told The Washington Post in 1998. “I’m proud of my career, the first one, and I’m proud of the other two, too.”

The simplistic plots of Miss Temple’s movies often cast her as a motherless tyke who found happiness and shared it with others. She first sang her signature song, “On the Good Ship Lollipop” in the movie “Bright Eyes,” one of nine films she made in 1934.

“Little Miss Marker” and another movie released that year, “Stand Up and Cheer!,” made her a national sensation. She had appeared in 20 films by the time she was 6. Miss Temple was 13 before she learned that Hollywood publicists had trimmed a year off her age, making her appear one year younger than she actually was.

An endearing role came in “Curly Top” (1935), in which Miss Temple played an orphan and sang “Animal Crackers in My Soup.” One of her most memorable movie moments came in “The Little Colonel” (1935), an Old South story in which tap dancer Bill “Bojangles” Robinson played her sidekick. Their staircase dance together remains one of the iconic movie scenes of the period and was one of the first times black and white actors appeared on equal terms in the same film.

Miss Temple called Robinson “Uncle Billy” and made three other films with him, including “Rebecca of Sunnybrook Farm.”

Miss Temple was “in perpetual motion — dancing, strutting, beaming, wheedling, chiding, radiating, kissing,” film historian Charles Eckert wrote in 1974. “And since her 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.”

The head of the struggling 20th Century Fox studio, Darryl F. Zanuck, worked to make a national sensation out of his young star. Products endorsed by Miss Temple were sold in the millions, and her popularity kept the studio from going under.

Luminaries who paid visits to Miss Temple in Hollywood included Amelia Earhart, Albert Einstein, J. Edgar Hoover and Eleanor Roosevelt. She received an honorary child-sized Oscar in 1935.

“As long as our country has Shirley Temple,” Franklin Roosevelt said, “we will be all right.”

Miss Temple made her 44th and final movie as a child star, “The Blue Bird,” in 1940, when she was 12. By then, she had outgrown the role of the winsome little girl. She was finally able to lead the life of an ordinary person and enrolled in school for the first time.

She had limited success with the few films she made as a teenager and young adult, such as the World War II melodrama “Since You Went Away” (1944) and “The Bachelor and the Bobby Soxer” (1947), opposite Cary Grant and Myrna Loy.

She appeared in director John Ford’s “Fort Apache” (1948), with John Wayne and Henry Fonda, playing the love interest of her first husband, a young actor named John Agar. They were married in 1945, allowing her to escape the tight control of her parents.

She had a daughter at 18, but she and Agar soon divorced. She later met Charles A. Black, a California businessman who had never seen any of her movies. After their marriage in 1950, the couple briefly lived in Bethesda while her husband was based at the Pentagon with the Navy.

Her marriage to Black introduced her to the world of politics and diplomacy, and Mrs. Black campaigned on behalf of Dwight D. Eisenhower and Richard M. Nixon.

Mrs. Black ran in a losing bid for the U.S. House of Representatives as a Republican in a special election in 1967. Two other prominent California politicians at the time, U.S. Sen. George L. Murphy (R) and Gov. Ronald Reagan (R), who was elected president in 1980, had been actors who had appeared in movies with the young child star.

“Politicians are actors, too, don’t you think?” Mrs. Black once said. “Usually if you like people and you’re outgoing, not a shy little thing, you can do pretty well in politics.”

In 1969, Mrs. Black was appointed a delegate to the United Nations by President Nixon. After Nixon’s resignation in 1974, Vice President Gerald R. Ford named Mrs. Black ambassador to Ghana. She later served briefly as chief of protocol of the United States, an advisory position at the State Department, in 1976 and 1977. In 1989, Reagan named her ambassador to Czechoslovakia, where she served three years as the country emerged from decades of communist rule.

After undergoing a mastectomy in 1972, Mrs. Black gave a news conference from her hospital room and later wrote about her experience in McCall’s magazine. She was among the first celebrities to discuss breast cancer in a public forum.

“I did it because I thought it would help other women, my sisters,” she told The Post in 1998. Within two weeks, she was back on the job with the White House Council on Environmental Quality.

Shirley Jane Temple was born in Santa Monica, Calif., on April 23, 1928. Her father was a banker and her mother a housewife who thought her daughter was destined to be in show business.

The young Miss Temple was taking dance classes by the time she was 3. She made her first film appearances in “Baby Burlesks,” a series of one-reel shorts that parodied movie stars of the day.

In her 1988 autobiography, “Child Star,” Mrs. Black wrote that she once asked for an accounting of her investments. She discovered that, of more than $3 million she had made since childhood, she had only about $30,000 to her name. Half her earnings had gone to her parents and much of the rest paid the living expenses of other family members and a dozen household workers, she said. Despite a court order, she wrote, her father failed to deposit money in her trust account.

“For reasons some may find inexplicable, I felt neither disappointment nor anger,” she wrote. “Perhaps years spent ignoring such matters had insulated me from disillusion.”

She and her husband, an official with the Stanford Research Institute (now SRI International), settled near San Francisco in the 1950s. Her husband died in 2005. Survivors include a daughter from her first marriage; two children from her second marriage; a granddaughter; and two great-granddaughters.

Mrs. Black, who had a brother with multiple sclerosis, began raising funds for the National Multiple Sclerosis Society in the 1950s. She served in the 1960s as the organization’s president, which fed her growing interest in public service.

She did not make another feature film after 1949 and increasingly withdrew from the world of show business. From 1958 to 1962, she was the host of “Shirley Temple’s Storybook,” an NBC-TV series in which she narrated and sometimes acted in adaptations of children’s tales. She also appeared in a 1965 situation-comedy pilot, “Go Fight City Hall,” which was filmed at the same studio where she had made many of her films three decades earlier.

As Miss Temple grew up and evolved into Mrs. Black, she remained relatively untainted by her early fame. She never resented the demands placed on her by her parents or studio and seemed to take joy in the hard work behind the song-and-dance routines that made her America’s littlest sweetheart.

“Most important of all, I was at peace with myself,” she wrote in her autobiography. “I just stood there in my socks, paid attention and worked with an uncluttered pose.”

Matt Schudel contributed to this report.