In the minutes after the motion to vacate against McCarthy, Rep. Patrick McHenry, R-N.C., was named as speaker pro tempore, an interim role to lead the chamber until another speaker is elected at a future point.

McHenry is a top McCarthy ally and chairman of the House Financial Services Committee.

He recessed the House for caucus meetings.

Eight Republicans voted to take away McCarthy's gavel.

In addition to Gaetz, who introduced the motion to vacate, the following Republicans voted to oust McCarthy: Reps. Andy Biggs of Arizona, Ken Buck of Colorado, Tim Burchett of Tennessee, Eli Crane of Arizona, Bob Good of Virginia, Nancy Mace of South Carolina and Matt Rosendale of Arizona.

Every Democrat present also supported the motion to vacate.

In a 45-minute roll call vote, the House moved to oust McCarthy as speaker.

The final vote was 216 to 210 in favor of Gaetz's motion to vacate, with eight Republicans joining Democrats.

"The office of speaker of the House of the United States House of Representatives is hereby declared vacant," said presiding officer Rep. Steve Womack.

It is the first time in U.S. history that the speaker of the House has been booted from the post, putting the chamber in unprecedented territory.

Republican rebels appear to have enough votes to remove McCarthy as speaker, given that Democrats joined them, though the vote is ongoing.

Now-former Speaker McCarthy addressed reporters from Capitol Hill on Tuesday night where he looked back at his years in Republican leadership, touted his record -- and struck an optimistic if ambiguous note about his future.

"I believe I can continue to fight," McCarthy said, while noting that he will not run again for speaker after he lost a historic vote on the motion to vacate earlier in the day.

"My goals have not changed. My ability to fight is just in a different form," he said, later adding, "I'll never give up on the American people. That doesn't mean I have to be speaker."

McCarthy also swiped at the conservative rebels who ousted him from his role -- stressing that they were just 4% of the GOP conference -- and claimed that Gaetz was acting out of a personal sense of grievance in pushing him out, which Gaetz denies.

Despite the defeat he suffered from within his own party, McCarthy sounded largely sanguine about his political career.

He contended that the Democratic minority deciding to vote against him had made a "political decision" that undercut the ability of the House to govern.

"My fear is the institution fell today," he said.

Still, in largely valedictory remarks, he pointed back to work to cut government spending, expand his party's base and increase their majority in Congress, including by electing more women and minorities.

"I feel fortunate to have served the American people," he insisted. "I leave the speakership with a sense of pride, accomplishment and, yes, optimism."

-ABC News' Adam Carlson