The Homestead Act on display at the Heritage Center is considered one of the national top 100 documents.

Unlike many of the nation's most important papers, there's only one copy and it had not been on display since 1979. And that translates to "handle with care."

There were a lot of stringent guidelines that had to be met before the State Historical Society of North Dakota could borrow the Homestead Act - temperature, humidity, light levels, according to Genia Hesser, curator of exhibits at the SHSND.

A special box had to be made to carry the document, and it traveled via a museum carrier service, which assigned two people to travel with the document, and "They didn't leave the vehicle" between Washington, D.C., and Bismarck, Hesser said. It also was tracked by satellite.

It took 12 months of negotiations, and $23,000 to get and keep the document in North Dakota.

The most frequently asked questions by visitors to the exhibit, says Mark Halvorson, curator of collections research at the Heritage Center, is "Why is it so dark?"

The document, already rather faded, is light sensitive. No flash photography is allowed. The exhibit must not be exposed to more than three candles of light. The humidity must be 45 percent, give or take 5 percent.

The paper at the time of the Civil War was not made from wood pulp, but rather from linen or cotton.

The Homestead Act will remain on display here through Nov. 10.