By Brad Segall

DOYLESTOWN, Pa. (CBS) — An unusual and rare piece of American history was on display Wednesday in Doylestown for the 4th of July holiday.

READ MORE: 4 People Killed, 2 Possibly Unaccounted For In Pottstown House Explosion, Officials Say

During Fonthill Castle’s Old-Fashioned 4th of July Celebration, people were able to get a glimpse of American history. One of only two known authentic copies of the Declaration of Independence was on display.

The exhibit allowed the public a rare opportunity to see the document as it might have looked in 1776. Noted Bucks County historian Tom Lingenfelter discovered it and calls it the most faithful and perfect copy in existence today.

See related story.

READ MORE: PHL Expects 500,000 Passengers To Come Through Airport During Memorial Day Weekend

“You can go see the original in Washington D.C.,” says Lingenfelter. “But you can’t get that close to it and you can’t read it because it’s damaged so bad. It’s basically an old piece of sacred leather.”

Lingenfelter says the copy is a mirror image of the original and was created through the anastatic process.

“It was made from the original in 1846 by a chemical process where they put a weak acid solution on the original and place a zinc plate over it and got a negative image into the zinc plate which they used to print from,” he explains.

Lingenfelter says a second anastatic copy is housed at Independence Hall, but is not on display. The nearly flawless copy of the now unreadable original was on display from noon until 4 p.m. on Wednesday (Independence Day).

MORE NEWS: CBS3 SummerFest: Chandler Lutz's Favorite Spots Along The Wildwood Boardwalk