Unbeknownst to Anna Plumstead, her attic in Wiscasset, Me., held a treasure: one of the earliest copies of the Declaration of Independence, delivered to her town in 1776 as part of a campaign to spread its message through the original 13 colonies.

After Ms. Plumstead died in 1994, the document was sold at an estate auction. It changed hands several times, ending up with a private collector in Virginia who paid $475,000 for it in 2001. Now Maine is seeking to reclaim it, citing a state statute that says a public document remains public until explicitly relinquished by the government.

“In our view it belongs to the community,” said William Stokes, a deputy state attorney general who will represent Maine at a trial next month in a suit filed by the collector. “It got separated from the community through the passage of time, but our position is it never belonged to anyone other than the town of Wiscasset.”