Capitol Hill on Thursday was mourning the unexpected death of Democratic Rep. Elijah Cummings of Maryland, as lawmakers in both parties saluted the veteran Chairman of the House Oversight Committee, who died early this morning at a hospice facility in his home town of Baltimore. Cummings had risen to the forefront of Congress in recent months as part of Democratic Party efforts in the U.S. House to investigate President Donald Trump and his administration. “When the history books are written about this tumultuous era, I want them to show that I was among those in the House of Representatives who stood up to lawlessness and tyranny,” Cummings said last month about his support for the impeachment of President Trump. 'The Congress and the nation have lost one of the great ones,' said Rep. Gerry Connolly (D-VA). 'This is a heartbreaking loss for Baltimore, Congress, and our entire country,' said Rep. Mike Quigley (D-IL). 'Elijah Cummings was a good friend and a powerful advocate for what he believed,' said Sen. Roy Blunt (R-MO). First elected to Congress in 1996, Cummings had in recent years become the top Democrat on the House Oversight Committee, sparring first with Republican investigations of the Obama Administration, and then taking the lead on investigations of President Trump and his administration. “The news that our friend and colleague Elijah Cummings has passed away marks a sad day for the members of the United States Congress, the people of Baltimore, and the entire nation,” said Rep. Liz Cheney (R-WY). In a statement released by aides to Cummings, his staff gave few details on his health troubles, saying that Cummings had died around 2:30 am on Thursday, in a hospice care facility, where the Maryland Democrat had been treated for 'longstanding health challenges.' It had been obvious to reporters in recent months that Cummings was facing some sort of health challenge, as he was using a wheelchair in the halls of Congress, and then a walker to make his way on to the floor of the House. But in interviews with reporters in the Speaker's Lobby just off the House floor, his voice still seemed strong, and gave no hint of immediate medical troubles. 'We're going to uphold the rule of law,' Cummings told me and other reporters in mid-May, as he outlined efforts to get information from the White House, which were routinely stonewalled by the Trump Administration. Cummings had returned after Labor Day, but had missed most votes after mid-September. Earlier this year, Cummings had drawn the ire of President Trump over investigations of the White House, as Mr. Trump called the Maryland Democrat a racist. “His loss will be felt across our country,” said Rep. Chrissy Houlihan (D-PA). Throughout the Mueller investigation - and other probes of the Trump Administration, Cummings had repeatedly urged voters to consider the totality of the situation involving President Trump, as he openly expressed concern about damage to the underpinnings of the federal government. “We are going to uphold the rule of law,” Cummings told a group of reporters in May. “Ladies and Gentlemen, we are in search of the truth,” Cummings said.