Cars exit and enter US Army facility Fort Leavenworth in Leavenworth, Kansas, on May 17, 2017. After seven years behind bars, US Army Private Chelsea Manning will walk out of the security gates of the Fort Leavenworth military prison, finally able to complete her transition as a free, openly transgender woman. Pic/AFP

Chelsea Manning, the transgender US soldier convicted of espionage for providing national security secrets to Wikileaks, was released from a military prison on Wednesday.