"This is done," Obama said, smacking his hand on the document after using pen after pen after pen to ink his name.
"We are not a nation that says 'don't ask don't tell,' we are a nation that says 'out of many, one,'" Obama said. "We are a nation that believes all men and women are created equal."
President Obama's signing of the landmark repeal of the military's "don't ask, don't tell" policy was a major victory to gay rights advocates and fulfilled a campaign promise to end the practice that was called discriminatory.
Obama said he was honored to sign a law that will "will strengthen our national security and uphold the ideals that our fighting men and women risk their lives to defend."
"No longer will tens of thousands of Americans in uniform be asked to live a lie or look over their shoulder," Obama said.
The signing doesn't immediately implement the repeal, but begins a process for ending the ban. The new law requires the president, along with Defense Secretary Robert Gates and Joint Chiefs of Staff Chairman Adm. Michael Mullen, first must certify to Congress in writing the U.S. armed forces have drafted necessary new policies and regulations and are ready to operate with openly gay, lesbian or bisexual men and women in military service. The certification also must affirm the changes will not hurt troop readiness, cohesion or military recruitment and retention.
Recognizing that with any change "there's apprehension," Obama said he had "every confidence" in the professionalism and patriotism of military service personnel.
Speaking to gay men and women, Obama said their military service "demanded a particular kind of sacrifice … (with) the added burden of secrecy and isolation. … As the first generation to serve openly, you will stand for all of those who came before you and you will serve as role models" to those who follow.
The ceremony was interrupted many times by raucous applause and shout-outs, including, "Yes we did."
When introducing Obama, Vice President Joe Biden called Wednesday "a good day. A very good day."
"By repealing 'don't ask, don't tell' today, we take a big step toward fostering justice, fairness and consideration," Biden said.
"It is both morally and militarily the right thing to do," Biden said.
While noting all the military leaders who supported the repeal, Biden singled out dais-mate Mullen, calling him "a stand-up guy" and triggering a long and loud round of applause from the audience.
Celebrity Families of 2014 [PHOTOS]