(CNN) -- Illinois Sen. Tammy Duckworth made history on Thursday as she became the first senator to cast a vote on the Senate floor with her newborn by her side.
Senate lawmakers narrowly voted, 50 to 49, to confirm GOP Rep. James Bridenstine to be the next NASA administrator. Duckworth voted against Bridenstine.
"It feels great," Duckworth told reporters as she entered the Capitol. "It is about time, huh?"
She also thanked colleagues for passing the rule change.
"I think it's historic, I think it's amazing," Duckworth said.
When she was on the Senate floor, a group of senators including Sens. Amy Klobuchar, Chuck Schumer, Mitch McConnell, Claire McCaskill, Maria Cantwell and Jeff Flake, came to congratulate her and meet her baby.
At one point, Klobuchar looked emotional while she was grinning looking at Duckworth and her newborn baby. She is the top Democratic member of the Senate Rules Committee, who worked with Chairman Roy Blunt of Missouri to change the longstanding rules to allow newborns -- for the first time -- onto the Senate floor during votes.
When Duckworth was leaving the chamber, the crowd of congressional reporters watching from the press seating cooed at her baby.
While it happened, Schumer turned to the reporters, put a hand to his mouth and said with a smile, "The press is finally interested in something worthwhile."
The vote comes one day after the Senate changed longstanding rules to allow newborns onto the Senate floor during votes for the first time. The rule change, voted through by unanimous consent, was done to accommodate senators with newborn babies, allowing them now to be able to bring a child under 1-year-old onto the Senate floor and breastfeed them during votes.
Duckworth, who is taking her unofficial maternity leave in Washington, DC, spearheaded the push for the rule change. She gave birth to her second child, Maile, 10 days ago.
Earlier on Thursday, the lawmaker tweeted: "May have to vote today. Maile's outfit is prepped. Made sure she has a jacket so she doesn't violate the Senate floor dress code requiring blazers. Not sure what the policy is on duckling onesies but I think we're ready."
The social media post was accompanied by a photo of the potential outfit.
Duckworth's dress code joke referred to Capitol Hill's previous rule, which required women -- reporters and lawmakers -- to wear dresses and blouses with sleeves if they want to enter certain areas.
Speaker Paul Ryan announced last year he would change the dress code after a reporter was denied access to a room because she had on a sleeveless dress.
Ryan's press secretary AshLee Strong tweeted a response to Duckworth on Thursday: "Senator, It took some drama but Maile and her sleeveless self are welcome on the House floor!"