The Government of the United States, a concern that has been running more or less smoothly since April 1, 1789, is closed until further notice. Here's what you need to know. First, why? The House and Senate failed to agree on a bill to fund the government for the fiscal year. In a nutshell, there's no money to pay the people who do many of the jobs that make the government work. What does this mean? Government employees are divided into "essential" and "non-essential." And some parts of government receive multi-year funding. So the "essential" parts of government will keep functioning. So will the institutions that receive multi-year funding. So if you know anyone who gets Social Security, they'll still get it, because Social Security funding does not come from the annual budget and because the Postal Service will still be open for business (its money comes from postage revenues, not Congress). If you or anyone you know is taking a flight anywhere anytime soon, take heart: there will still be air traffic controllers on the job. They are considered essential. So is the military and the FBI. Ironically, the House and Senate will still receive their paychecks. So what's closed? Parks and museums, for a start. The Environmental Protection Agency will more or less shut down. Cities and towns will stop receiving money for public housing. The Veterans Administration won't be able to process many benefits. The Department of Agriculture will stop funding WIC, the program that provides pregnant women and new mothers assistance with getting nutritional food and health care. And all food inspection will stop. Strangely, the people who determine the safety of the nation's food supply are considered "non-essential." Has this every happened before? You bet. Actually, 18 times. Most recently, the federal government was closed for 28 days in 1995 and '96. Here's a complete list of all the times and ways our government has ground to a screeching halt... Representative Rush Holt of New Jersey has a list of these and other possible effects of a government shutdown. Entrepreneur has a good Q & A on the shutdown here. And if you want to be really well-informed on this debacle, USA Today has 66 questions and 66 answers.