An Indiana soldier’s rare first-edition copy of volume one of “The Federalist” sold for $80,000 at auction Tuesday, netting him an unexpectedly large profit before he’s deployed on his second tour in Iraq.

Indiana National Guard Capt. Nathan Harlan was a 16-year-old high school junior when he paid $7 for a leather-bound copy of the book that was part one of a two-volume 1788 book of essays calling for the U.S. Constitution’s ratification.

Nineteen years later, his wise purchase at a South Bend flea market back in 1990 earned the divorced father of three a more than 11,000-fold return.

Harlan, 35, said he finished his training Tuesday at south-central Indiana’s Camp Atterbury in time to log onto Heritage Auction Galleries’ Web site and watch final bidding on the book that he had kept in a shadowbox until recently.

“I was yelling as the bids were coming in — it was like watching the Super Bowl for me,” said Harlan, who lives in Granger. “The outcome was way beyond my expectations.”

The Dallas auction house said the winning bidder asked to be identified only as a resident of the Baltimore area.

Harlan intends to save most of the $80,000 after paying a few bills. But he said he’s considering adding to the college funds of his two sons and daughter.

“It’s a rare opportunity when someone gets a windfall like this,” he said.

Harlan will get all the proceeds because Heritage is waiving its standard 20 percent seller’s commission in recognition of his military service.

Harlan deploys this summer for up to a yearlong deployment to Iraq with the 140-soldier 38th Combat Aviation Brigade and said he likely won’t get the money from the auction until he’s on his way overseas.

Prior to the auction, Heritage Auction Galleries conservatively estimated the book would bring $8,000 to $12,000, with a bid possible in the range of $20,000 to $30,000.

The two-volume set of “The Federalist” was published months after the Constitution was drafted in September 1787 in Philadelphia.

The essays were penned by James Madison, Alexander Hamilton and John Jay, all of whom used the same pseudonym to focus attention on their pro-ratification arguments.

“It turned out in retrospect to be a very important summation of the political thought of that period, and one of the great political documents that’s come out of America,” said Mark Dimunation, chief of the rare book and special collections division at The Library of Congress.