Jenner followed up with a second tweet, welcoming her new identity: "I'm so happy after such a long struggle to be living my true self. Welcome to the world Caitlyn. Can't wait for you to get to know her/me."
Caitlyn Jenner is introduced to the world
Caitlyn Jenner shatters President Obama's Twitter record by reaching 1 million followers fastest
In this June 1, 2015 photo, a journalist looks at Vanity Fair's Twitter site with the Tweet about Caitlyn Jenner, who will be featured on the July cover of the magazine. Caitlyn Jenner, the transgender Olympic champion formerly known as Bruce, on Monday unveiled her new name and look in a sexy Vanity Fair cover shoot -- drawing widespread praise, including from the White House. Lesbian, gay, bisexual and transgender campaigners -- and many well-wishers -- welcomed the high-profile debut, as did the 65-year-old Jenner's family, which includes the media-savvy celebrity Kardashian clan. 'I'm so happy after such a long struggle to be living my true self,' Jenner wrote in her first tweet after the magazine released the July cover photo by renowned photographer Annie Leibovitz. (Photo credit Mladen Antonov, AFP/Getty Images)
Great day yesterday for Father's Day. We had so much fun off-roading. So much love and support! Love my family!
The best thing about being a woman is the prerogative to have a little fun #Caitlyn #ServingCindyMcCainRealness #TransRepubsAreTheBestRepubs (dying for that old school glamour waist to breast ratio)
A photo editor views the July cover of Vanity Fair featuring Caitlyn Jenner on June 1, 2015 in Westwood, California. Formerly known as Bruce Jenner, Caitlyn Jenner is an Olympic atlete who came out publicly as transgender in a televised interview with Diane Sawyer. (Photo by Frazer Harrison/Getty Images)
Caitlyn Jenner poses for Annie Leibovitz on the cover of Vanity Fair #CallMeCaitlyn http://t.co/NRyh6R09RR http://t.co/GO1ZgJJKBR
SO gorgeous!!!! RT #BruceJenner's first photo as a woman revealed! Meet #CaitlynJenner HERE! http://t.co/eXq7FSK4Vl #CallMeCaitlyn
Finally free. This made me stop. The feeling of freedom. You go @Caitlyn_Jenner! https://t.co/P4nDwltjxi
#CallMeCaitlyn: Caitlyn Jenner was photographed by Annie Leibovitz for @VanityFair cover http://t.co/vKHoOCvBzO
CAITLYN!!!!!!!!!! Love this. So happy for her. https://t.co/YOo4kdBOJl
Caitlyn? But why isn't it Kaitlyn with a K? (Bravo, Ms. Jenner!)
❤️RT @VanityFair: I’m not doing this to be interesting. I’m doing this to live #CallMeCaitlyn http://t.co/Fkpu3xYYX5 http://t.co/cFKkBeQN4V
#CaitlynJenner has truly broken the Internet. What a moment.
❤️🔥🔥🔥🔥 YAS 🔥🔥🔥🔥❤️
Caitlyn Jenner for Vanity Fair 📷 Annie Leibovitz! How beautiful! Be happy, be proud, live life YOUR way!
Within the first hour, Jenner had gained 284,000 followers and become a trending topic. She hit the one million mark in just under four hours. At this time, she doesn't follow any other accounts on Twitter.
I'm so happy after such a long struggle to be living my true self. Welcome to the world Caitlyn. Can't wait for you to get to know her/me.
Jenner's social media achievement beats a record previously held by President Barack Obama, who launched the @POTUS handle last month. The account, associated with the presidential office, reached one million followers in under five hours.
Along with her Twitter account, Jenner debuted a verified Facebook page and Instagram account. She shared similar messaging across all social media platforms.