"We made history tonight," the 33 year-old from Northern Virginia, proudly declared at newly-elected Virginia Gov. Ralph Northam's election night party. "We won because I am a transgender woman...because of my inherent identifiers not despite them. I never ran away from them. I championed them."
The former journalist defeated 13-term Virginia House Delegate Bob Marshall, 54 to 45 percent.
"Danica will bring a reporter's eye to Richmond, and we eagerly anticipate her results-oriented approach to deliver for her constituents," the Virginia House Democratic caucus leader David J. Toscano and caucus chairwoman Charniele Herring said in a statement.
Marshall, author of Virginia's "bathroom bill," a measure that would have restricted the bathrooms transgender people can use, thanked his longtime supporters in a statement on Facebook.
"Thank you all for your support over the years and this last election. For 26 years I've been proud to fight for you, and fight for our future. Though we all wish tonight would have turned out differently, I am deeply grateful for your support and effort over the years," the statement read. "I'm committed to continue the fight for you, but in a different role going forward."
The race was one of the year's most high profile and drew national and international attention and big money to the northern Virginian district.
During the campaign, Marshall and other Republicans frequently misidentified Roem's gender and put out campaign ads that also attacked her transgender identity.
"No matter what you look like, where you come from, how you worship or who you love, if you have good public policy ideas, if you're qualified for office, you have every right to bring your ideas to the table," she said.