Marilyn was born Norma Jeane Mortenson on June 1, 1926 in Los Angeles, California, to Gladys Baker. As the identity of her father is undetermined, she was later baptized Norma Jeane Baker. Gladys had been a film cutter at RKO studios, but psychological problems prevented her from keeping the job and she was eventually committed to a mental institution.
Norma Jeane spent most of her childhood in foster homes and orphanages until 1937, when she moved in with family friend Grace McKee Goddard. Unfortunately, when Grace's husband was transferred to the East Coast in 1942, the couple couldn't afford to take 16-year-old Norma Jeane with them. Norma Jeane had two options: return to the orphanage or get married.
On June 19, 1942 she wed her 21-year-old neighbor Jimmy Dougherty, whom she had been dating for six months. "She was a sweet, generous and religious girl," Jimmy said. "She liked to be cuddled." By all accounts Norma Jeane loved Jimmy, and they were happy together until he joined the Merchant Marines and was sent to the South Pacific in 1944.
After Jimmy left, Norma Jeane took a job on the assembly line at the Radio Plane Munitions factory in Burbank, California. Several months later, photographer David Conover saw her while taking pictures of women contributing to the war effort for Yank magazine. He couldn't believe his luck. She was a "photographer's dream." Conover used her for the shoot and then began sending modeling jobs her way.
The camera loved Norma Jeane, and within two years she was a reputable model with many popular magazine covers to her credit. She began studying the work of legendary actresses Jean Harlow and Lana Turner, and enrolled in drama classes with dreams of stardom. However, Jimmy's return in 1946 meant Norma Jeane had to make another choice- this time between her marriage and her career. Norma Jeane divorced Jimmy in June of 1946, and signed her first studio contract with Twentieth Century Fox on August 26, 1946. She earned $125 a week.
Soon after, Norma Jeane dyed her hair blonde and changed her name to Marilyn Monroe (borrowing her grandmother's last name). The rest, as the saying goes, is history.
Also this is a rather interesting article on CNN.com accompanied by unpublished photos of Marilyn Monroe.