When the country's largest private collection of Franklin Delano Roosevelt memorabilia goes up for auction next week in Dallas, one of the hottest lots will be a series of three watercolor sketches by artist Elizabeth Shoumatoff.

FDR was sitting for a portrait in his vacation cottage in Georgia on April 12, 1945, when to the painter's horror, he suddenly slumped forward in his chair. A short time later, the nation's 32nd president -- the only commander-in-chief in our nation's history to serve more than two terms -- lay dead of a cerebral hemorrhage at age 63.

Ms. Shoumatoff would use those progressively detailed watercolors, which captured Roosevelt in his naval cape and holding a scroll, to create the famous "Unfinished Portrait" that hangs in the Little White House museum in Warm Springs. The historic paintings, one of 568 lots being offered by Heritage Auction Galleries during the June 7 sale, would also serve as proof studies for a portrait of FDR that President Lyndon Johnson commissioned in 1967 for the White House.

Your average Joe, however, will probably find Lot No. 53250 much more fascinating, if a bit macabre. It contains the monogrammed sheets from FDR's deathbed at the Little White House, which chief housekeeper Hoke Shipp had the fortitude to sock away until 1985, when they passed into a private collection. Minimum bid: $5,000.

"He was going to donate them to the Little White House, but they made him mad so he kept them," said Michael Riley, the auction house's chief cataloger and historian.

Considering the country is in the middle of a presidential campaign, and PBS just aired a two-part series on FDR's life, interest in the sale is expected to be exceptionally high. Yet even in a nonelection year, said Mr. Riley, Franklin Roosevelt memorabilia is a perennial favorite among collectors.

"Most people look at him as the person who got us out of the Great Depression and World War II," he noted. "He has just a unique place in American history."

Auction items include hundreds of letters, photographs and pop culture items from the Roosevelts' lives, both from his prepresidential years and during his more than 12 years in office. They come from the private collection of Joseph and Deborah Plaud of Whitinsville, Mass., who until recently ran the nonprofit Franklin D. Roosevelt American Heritage Center & Museum at Union Station in nearby Worcester.

A forensic clinical psychologist, Dr. Plaud caught the FDR collecting bug early. His first purchase was in junior high, when he bought a picture of the Roosevelts for about $50. By the mid-1990s, his interest had shifted from souvenir-type items to more serious collectibles that spoke to Roosevelt's many accomplishments, chief among them the New Deal. He opened the museum in 2004, when his many documents, pictures and knicknacks outgrew its space in his home.

When the museum had to give up its space in 2007 for another tenant and Dr. Plaud was unable to find another location, the couple decided to offer their historical archive to the public rather than place it in storage.

Ms. Shoumatoff's framed studies could sell for as much as $80,000 to $120,000, according to the gallery's Web site, while an archive of 47 signed checks from FDR's personal bank account during the last six months of his life, with the final check register, is estimated at $40,000 to $60,000. But talk about a rare glimpse into the Roosevelts' personal spending habits: the checks include one for $52.50 written by the president to the New York State Tax Commission on Jan. 5, 1945 to cover an "error" he made in his 1942 state tax returns and a $125 donation on Oct. 11, 1944 to the Community War Fund. It also includes the last check he ever signed, $1,800 for Eleanor's monthly allowance, three days before his death.

Many other pieces, though, will sell for substantially less. For instance, the president's trademark, size 7 1/4, gray felt "Kings Ransom" fedora is estimated at $4,000 to $6,000, while a gold Tiffany wristwatch given to him on his 63rd birthday by five White House correspondents is valued at between $10,000 and $15,000. Eleanor's metal Bloomingdale's charge card in its original leather carrying case is expected to bring between $900 and $1,200.

Other items on the block include the gold compact FDR gave to his wife for Christmas in 1934; the congratulatory concession telegram Alf Landon sent him on election night 1936; a short "snorter" dollar bill Roosevelt signed on his way to the Teheran Conference in 1943; and dozens and dozens of signed letters and other correspondence. You can also bid on a land deed signed in 1696 in which five Native American chiefs sold their land to early Dutch settlers. The 15,000 acres of land eventually became Hyde Park, where FDR was born and buried.

And if nothing catches your fancy this time around? The Plaud collection is so large it's being sold in two installments; a second auction of a similar size will be held later this fall.

"It's all Roosevelt, all the time on this one," said Mr. Riley.

For more information on Heritage Auction Galleries' auction of The Plaud Collection of Eleanor & Franklin Roosevelt Items, call 1-800-872-6467 or visit www.HA.com/6001.