Express Auction Marketing Specialists will hold an auction for Lands End on Severn River at 1 p.m. on Sunday, Aug. 23 at the waterfront home.

Opening bid for the estate is $500,000, said Larry Makowski, who owns Gloucester-based Express with his wife, Linda. The property was once appraised for $2.2 million, they said, and its most recent county assessment was $1,240,000.

The Makowskis are not just trying to auction a house, which the owners have tried to sell for several years, but are also handling the transaction for what’s a historic property that is listed on the National Register of Historic Places. Captain John Sinclair, a highly decorated Revolutionary War privateer, built the original home about 1795 on land that was part of the Robins Patent granted in 1637.

Sinclair’s estate originally had 600 acres, the Makowskis said, of which a portion of that land today is the nearby Captain Sinclair Recreational Area being developed by the Middle Peninsula Public Access Au...