Congress blew by a midnight deadline to pass a crucial spending bill, triggering the beginning of a partial government shutdown – the first in 17 years.

The failure means the gears of the federal government will start to slow down on Tuesday, though hundreds of thousands of federal workers will remain on the job. Though it's been a long time since the last one, this marks the 18th shutdown since 1977.

Lawmakers missed the deadline after being unable to resolve their stand-off over ObamaCare, despite a volley of 11th-hour counterproposals from the House. Each time, Senate Democrats refused to consider any changes to ObamaCare as part of the budget bill.

House Republicans, for their part, refused to back off their demand that the budget bill include some measures to rein in the health care law – a large part of which, the so-called insurance “exchanges,” goes into effect on Tuesday.

As House Republicans endorsed one more counterproposal in the early morning hours, lawmakers spent the final minutes before midnight trying to assign blame to the other side of the aisle. Republicans are no doubt wary of the blowback their party felt during the Clinton-era shutdown, while Democrats were almost eager to pile the blame on the GOP.

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“This is an unnecessary blow to America,” Senate Democratic Leader Harry Reid said.

House Speaker John Boehner claimed that Republicans are the ones trying to keep the government open but “the Senate has continued to reject our offers.”

Ahead of the deadline, the White House budget office ordered agency heads to execute an “orderly shutdown” of their operations due to lack of funds. Americans will begin to feel the effects of a shutdown by Tuesday morning, as national parks close, federal home loan officers scale back their caseload, and hundreds of thousands of federal workers face furlough.

The question now is how long the stand-off will last. Congress is fast-approaching another deadline, in mid-October, to raise the debt limit or face a U.S. government default. Lawmakers presumably want to resolve the status of the government swiftly in order to shift to that debate.

Throughout the day Monday, lawmakers engaged in a day-long bout of legislative hot potato.

The House repeatedly passed different versions of a bill that would fund the government while paring down the federal health care overhaul. Each time, the Senate said no and sent it back.

As a last-ditch effort, House Republicans early Tuesday morning endorsed taking their disagreement to what’s known as a conference committee – a bicameral committee where lawmakers from both chambers would meet to resolve the differences between the warring pieces of legislation.

The latest House bill, which the Senate shot down late Monday, would delay the law's individual mandate while prohibiting lawmakers, their staff and top administration officials from getting government subsidies for their health care.

The House voted again to endorse that approach early Tuesday and send the bill to conference committee.

“It means we're the reasonable, responsible actors trying to keep the process alive as the clock ticks past midnight, despite Washington Democrats refusal - thus far - to negotiate,” a GOP leadership aide said.

Reid, though, said the Senate would not agree to the approach unless and until the House approves a “clean” budget bill.

The rhetoric got more heated as the deadline neared.

“They’ve lost their minds,” Reid said of Republicans, in rejecting the latest proposal.

“Senate Democrats have made it perfectly clear that they’d rather shut down the federal government than accept even the most reasonable changes to ObamaCare,” Senate Republican Leader Mitch McConnell countered.

Amid the drama, President Obama said he was holding out hope that Congress would come together "in the 11th hour."

Such a deal did not come to pass.

A prior Republican effort to include a provision defunding ObamaCare in the budget bill failed. House Republicans then voted, early Sunday, to add amendments delaying the health care law by one year and repealing an unpopular medical device tax.

The Senate, in a 54-46 vote, rejected those proposals on Monday afternoon.

At this stage, congressional leaders are hard at work trying to assign blame.

Democrats have already labeled this a "Republican government shutdown." But Republicans on Sunday hammered Reid and his colleagues for not coming back to work immediately after the House passed a bill Sunday morning.