In a dramatic procession across the US Capitol, House Democrats have carried the formal articles of impeachment against President Donald Trump to the Senate, setting the stage for only the third trial to remove a president in American history.
Trump complained anew it was all a "hoax," even as fresh details emerged about his efforts in Ukraine.
The ceremonial pomp and protocol moved the impeachment process out of Speaker Nancy Pelosi's Democratic-run House to the Republican-majority Senate, where the president's team is mounting a defence aiming for swift acquittal.
"Today we will make history," Pelosi said as she signed the documents, using multiple pens to hand out and mark the moment. "This president will be held accountable."
Moments later the prosecutors walked solemnly through the stately hall, filing into the Senate back row as the Clerk of the House announced the arrival: "The House has passed House Resolution 798, a resolution appointing and authorising managers of the impeachment trail of Donald John Trump, President of United States."
The Senate will transform itself into an impeachment court at noon on Thursday.
The trial will play out before a deeply divided nation at the start of this election year as Trump seeks a second term and voters review his presidency.
Earlier Wednesday, the House voted 228-193, almost entirely along party lines, ending a weeks-long delay to deliver the charges with a tally reflecting the nation's split.
Senate Majority Leader Mitch McConnell pledged to have the Senate "rise above the petty factionalism" and "factional fervour and serve the long-term, best interests of our nation." He called it "a difficult time for our country."
The House impeached Trump last month alleging he abused his presidential power by pressuring Ukraine to investigate Democratic rival Joe Biden, using military aid to the country as leverage. Trump was also charged with obstructing Congress' ensuing probe.
Trump's political campaign dismissed the House effort as "just a failed attempt to politically damage President Trump leading up to his reelection."
The top Republican in the House, Kevin McCarthy of California, said Americans will look back on this "sad saga" that tried to remove the president from office with the "weakest case."
The seven-member prosecution team was led by the chairmen of the House impeachment proceedings, Reps. Adam Schiff of the Intelligence Committee and Jerry Nadler of the Judiciary Committee, two of Pelosi's top lieutenants.
Ahead of Wednesday's session, Schiff released new records from Lev Parnas, an associate of Trump lawyer Rudy Giuliani, about the Ukraine strategy, including an exchange with another man about surveilling Ambassador Marie Yovanovitch, who was later ousted.