In another historical moment for the Obama administration, the Senate on Tuesday evening confirmed the long-stalled nomination of Eric Fanning to be Army secretary.
Fanning thus becomes the first openly gay leader of any U.S. military service — a milestone not lost on gay rights groups and coming five years after the repeal of "don't ask, don't tell," which had prohibited gay and lesbian service members from being open about their sexuality.
"Eric Fanning's historic confirmation today as Secretary of the U.S. Army is a demonstration of the continued progress towards fairness and equality in our nation's armed forces," Human Rights Campaign President Chad Griffin said in a statement.
The voice vote to confirm, Fanning, 47, came after Sen. Pat Roberts, R-Kan., dropped his opposition in a dispute over Obama administration efforts to close the prison at Guantanamo Bay, Cuba, and transfer detainees to the United States.
Roberts said he received assurances from the administration in private discussions that the clock has run out on moving detainees to Fort Leavenworth, Kansas.
Rep. Nancy Pelosi, D-Calif., was among the first politicians to congratulate Fanning publicly Tuesday, tweeting that he is "capable, experienced & will lead with honor!"
A slate of senators from both parties joined in the praise for Fanning. Sen. Sherrod Brown, D-Ohio, tweeted that Fanning's selection is "an historic moment for #LGBT servicemembers," while Sen. Dan Sullivan, R-Alaska, tweeted that he "appreciated (Fanning's) recognition of Alaska's strategic importance & need for larger @USArmy."
Fanning served as the Army secretary's principal adviser on management and operation of the service. He was undersecretary of the Air Force from April 2013 to February 2015, and for half a year was the acting secretary of the Air Force.
Fanning's path to the post began roughly eight months ago, but was stymied when Roberts held up confirmation.
"Let me be very clear on this — as a veteran, a Marine — I support Mr. Eric Fanning for this post," Roberts said on the Senate floor late last month. "If the White House calls and assures me that terrorists held at Guantanamo will not come to Ft. Leavenworth, I will release the hold — immediately."
White House officials suggested Roberts was grandstanding and fellow senators pleaded with Roberts to lift his hold. Sen. John McCain, chairman of the Armed Services Committee — who calls Roberts a "good friend" — took the floor last month and pleaded with him to move the process along.
The pushback centered on the president's announcement of a long-anticipated pitch to Congress in February to close the detention facility at Guantanamo Bay. The Obama administration is considering 13 locations across the country, including seven existing prison facilities in Colorado, South Carolina and Kansas and six additional sites on current military bases.
Officials have said the plan doesn't highlight a preferred site.
A number of lawmakers — particularly Republicans — balked at the president's proposals.
However, Roberts remained entrenched in his opposition. In March, he introduced a Senate resolution rejecting any efforts to transfer detainees from Guantanamo Bay to American facilities.
But after changing his mind in allowing Fanning's confirmation to move forward, Roberts on the Senate floor reiterated his belief Tuesday that he always considered Fanning the right person to lead the military's largest branch, which currently has about 470,000 active troops.
"He will be a tremendous leader as Army secretary and will do great by our soldiers at Fort Leavenworth and Fort Riley," Roberts said prior to the vote.
—The Associated Press contributed reporting to this article.
This article first appeared on NBCNews.com.