"I collected as a child, and this was the stamp of my dreams," Mr. Hack said after the sale. He added that he viewed the stamp as a sound investment. "It's an icon of America."
The block went for $2,970,000, which is a new world's record. Forty bidders and observers who gathered for the sale at the Robert A. Siegel Auction Galleries.
After the auction, the seller, Kerby Confer, a Southern radio executive, who had remained anonymous during the 16 years he owned the block, identified himself.
Confer said he had a lifelong passion for collecting stamps and coins and was proud to have been a part of the stamp's history.
For more on the history and background the "Inverted Jenny," click here.