Courtney Whitmore is a junior member of the Justice League of America and the JSA All-Stars. She originally operated as Star-Spangled Kid using Sylvester Pemberton's Cosmic Converter Belt, but when Jack Knight left her the Cosmic Staff, she adopted the name Stargirl. With the belt and the staff, she carries on the legacies of Star-Spangled Kid and Starman.
Courtney was the daughter of Sam Kurtis and Barbara Whitmore, born and raised in sunny California. Her parents broke up, and Barbara found a new love: Pat Dugan. They moved to Blue Valley, Nebraska. Courtney did not like the move, and she did not like her new stepdad. She did make new friends quickly though, with Mary Kramer and Josh Hamman.
While rummaging through her stepfather's belongings, she found Sylvester Pemberton's old equipment. Realizing her stepdad used to be Stripesy, the only adult sidekick to a teen hero in history, filled her with joy, as she had a new means to get back at him and ridicule him. She donned a Star-Spangled outfit to a patriotic-themed spirit week dance to mock him, but they were attacked by Dragon King's minions. Dugan pulled out his newly built S.T.R.I.P.E. Armor to stop them, and they prevented the thugs from taking over. They decided they would form a duo, Star-Spangled Kid and S.T.R.I.P.E. 
The attack on the high school caught the attention of Oracle, who clued Robin in on the new legacy hero. Though they had little to go on, Young Justice traveled to Nebraska to take a look at the new hero. Their initial meeting was not smooth (as they kept thinking the S.T.R.I.P.E. armor was a robot) but in the end, they solved an alien invasion together.
Adventures in Blue Valley
In Blue Valley, most of her adventures involved Dragon King, and his daughter, Cindy Burman. Cindy was the most popular girl in school, and as evil as her father. She adopted the name Shiv, and became Courtney's arch nemesis.
When Jack Knight retired as Starman, he knew who to give his staff to. He had previously met Courtney, and was impressed how she managed during Klarion's antics. She had wielded the Staff then, so as he left for San Francisco to raise his son Kyle, he passed the staff, and the legacy of Starman to her. She added the Cosmic Staff to her arsenal, later deciding to adopt the name Stargirl, a name Mary had suggested to her when she first became a hero.
She only sporadically saw her biological father, Sam Kurtis, and when she did, it was not in a positive light. When she found him working as a low-level goon for the Royal Flush Gang, she broke all ties with him for good. She started acknowledging Pat as her father, which was cemented when she learned of Kurtis's death.
Stargirl was a much appreciated junior member of the Justice Society. She learned a lot from Power Girl, and had a brief fling with Billy Batson. That fact the rest of the Society did not know Captain Marvel was actually a fourteen year old hampered the relationship, and led to Captain Marvel quitting the JSA. Al Rothstein and Jakeem Thunder also had an affection for her. She did have feelings for Al, and even saw a vision of them being married in the future. When he was tried for the massacre in Khandaq, she told him she would wait for him.
Stargirl began attending college. She changed her equipment: her rod was compresses to a small cylinder, and when she activated it, her costume and belt appeared while the rod grew to full size. She also took driving lessons from Mr. Terrific.
The JSA was disbanded not long after since only three members remained. When the time was right, Green Lantern, Flash and Wildcat reformed the JSA, and Stargirl was inducted. She became friends with Ma Hunkel's granddaughter, Maxine Hunkel, and helped her form her identity, Cyclone.
When the JSA split up due to differences between the old guard and the new, Courtney decided to join the JSA All-Stars. At first she felt out of place because everyone was older than her, but Power Girl convinced her that they needed her, and that she was a role model to most of the members. During this time, Albert Rothstein was missing and Johnny Sorrow claimed to be in love with her. He took her to the subtle realms disguised as Atom Smasher in order to receive a kiss from the girl. The real Atom Smasher was tied up at a castle in the realms and the JSA All-Stars came to save her. Afterwards, Courtney continued her work with the All-Stars, also attempting to patch up her relationship with Albert, but they soon realized that they both had a need for space.
- Cosmic Converter Belt
- Star-Rocket Racer: Pat Dugan provided her with a car for her birthday. Although Courtney has yet to realize it, the car is actually a modified version of the original Star-Rocket Racer, once used by her predecessor Sylvester Pemberton.
- Stargirl was created by Geoff Johns, who is said to have based her personality on that of his sister who tragically died in TWA Flight 800. Johns is an avid fan of Captain Carrot and the Zoo Crew and Courtney's original outfit was quite similar to Zoo Crew member Yankee Poodle's.
- 320 Appearances of Courtney Whitmore (New Earth)
- 114 Images featuring Courtney Whitmore (New Earth)
- 5 Quotations by or about Courtney Whitmore (New Earth)
- Character Gallery: Courtney Whitmore (New Earth)
- Stargirl at dccomics.com
- Stargirl at Wikipedia.org
- Stargirl biography page at the Unofficial Guide to the DC Universe
- Stars and S.T.R.I.P.E. series index at DCU Guide
- Stars and S.T.R.I.P.E. series index at Comicbookdb.com
- Stars and S.T.R.I.P.E. series index at the Grand Comics Database Project
Justice Society of America member