Today will be the last day for Philadelphians and tourists to see historical sites like the Liberty Bell and Independence Hall for the foreseeable future, if leaders in Washington can't agree on a fiscal plan by midnight.

The federal government appears to be headed toward its first shutdown in nearly 20 years, as President Barack Obama and leaders in Congress are struggling to reach an agreement to fund federal agencies.

If a plan to avert a shutdown isn't reached today, all 401 national parks will close, according to a contingency plan released by the Department of the Interior.

That includes high-profile sites like Philadelphia's Independence National Historical Park -- which encompasses Independence Hall, the Liberty Bell and other attractions -- Yellowstone National Park and the Statue of Liberty, the department notes in a rundown of frequently asked questions about the potential shutdown.

All other national parks in Pennsylvania and New Jersey would also be affected, including the Flight 93 National Memorial, Gettysburg National Military Park, Valley Forge National Historical Park and New Jersey Pinelands National Reserve.

Across the country, all parks, visitor centers and other facilities would be closed in a shutdown, the National Park Service says. Education programs and other activities would be canceled, and permits for special events would be rescinded.

"Effective immediately upon a lapse in appropriations, the National Park Service will take all necessary steps to close and secure national park facilities and grounds in order to suspend all activities except for those that are essential to respond to emergencies involving the safety of human life or the protection of property," the contingency plan says.

The closure of the national parks, as well as the Smithsonian museums and National Zoo in D.C., would be among of the most visible early effects of a shutdown.

Other immediate effects include delays getting loans for low-to-moderate income borrowers and first-time homebuyers; the shutdown of the Special Supplemental Nutrition Program for Women, Infants and Children, known as WIC; the suspension of Internal Revenue Service audits and the agency's help lines; and delayed paychecks for military personnel.

The park service contingency plan says 21,379 of its 24,645 employees will be furloughed. Only those workers "absolutely required" to support "the protection of life, property, and public health and safety" will remain on duty.

During the government shutdown that lasted from Dec. 16, 1995, to Jan. 6, 1996, the closure of the national parks led to a loss of 7 million visitors and their tourism revenue to local communities, according to a Congressional Research Service report.

Contact Emily Babay at 215-854-2153 or Follow @emilybabay on Twitter.
Contact the Breaking News Desk at 215-854-2443 or Follow @phillynews on Twitter.