The federal government has shut down at the stroke of midnight Friday. That has halted all but the most essential operations and marred the one-year anniversary of President Donald Trump's inauguration in a striking display of Washington dysfunction.

With no apparent indications of a breakthrough in the Senate to avoid a government shutdown, the Capitol is illuminated in Washington, Friday evening, Jan. 19, 2018. (AP Photo/J. Scott Applewhite)

With no apparent indications of a breakthrough in the Senate to avoid a government shutdown, the Capitol is illuminated in Washington, Friday evening, Jan. 19, 2018. (AP Photo/J. Scott Applewhite)

Last-minute negotiations crumbled as Senate Democrats blocked a four-week stopgap extension in a late-night vote, causing the fourth government shutdown in a quarter century. Behind the scenes, however, leading Republicans and Democrats were trying to work out a compromise to avert a lengthy shutdown.

Office of Management and Budget Director Mick Mulvaney, is surrounded by reporters following a TV interviewed about a possible government shutdown at the White House, in Washington, Friday, Jan. 19, 2018. (AP Photo/Manuel Balce Ceneta)

Office of Management and Budget Director Mick Mulvaney, is surrounded by reporters following a TV interviewed about a possible government shutdown at the White House, in Washington, Friday, Jan. 19, 2018. (AP Photo/Manuel Balce Ceneta)

Congress scheduled an unusual Saturday session to begin considering a three-week version of the short-term spending measure.

Senate Majority Leader Mitch McConnell, R-Ky., arrives at the Capitol in Washington, Friday, Jan. 19, 2018, as a bitterly-divided Congress hurtles toward a government shutdown this weekend in a partisan stare-down over demands by Democrats for a solution on politically fraught legislation to protect about 700,000 younger immigrants from being deported. (AP Photo/J. Scott Applewhite)

Senate Majority Leader Mitch McConnell, R-Ky., arrives at the Capitol in Washington, Friday, Jan. 19, 2018, as a bitterly-divided Congress hurtles toward a government shutdown this weekend in a partisan stare-down over demands by Democrats for a solution on politically fraught legislation to protect about 700,000 younger immigrants from being deported. (AP Photo/J. Scott Applewhite)