Certain people unwittingly become eyewitnesses to momentous historical events. Elizabeth Shoumatoff, portrait painter to the rich and famous, was one of them.

Ms. Shoumatoff, a Russian émigré, was painting a portrait of President Franklin Delano Roosevelt when, while posing, he suffered the cerebral hemorrhage that killed him.

Roosevelt was sitting in a chair, his naval cape around his shoulders, signing documents in the small living room at the Little White House in Warm Springs, Ga. Some say he brushed his hand across his forehead and mentioned that he had a terrific headache. Ms. Shoumatoff always maintained that he said nothing before slumping over. Roosevelt was carried to his bed. His cardiologist, who was at the Little White House, tried to revive him, to no avail. He died on April 12, 1945.

Ms. Shoumatoff left the Little White House immediately, taking with her the unfinished portrait, as well as three watercolors she had painted a day or two earlier. The watercolors were rough drafts of the portrait so that she could get the color, composition and depth just right.

The oil painting eventually went back to the Little White House and has been on display there ever since. Ms. Shoumatoff, who died in 1980, kept the three watercolors. They were privately owned until this spring, when Dr. Joseph J. Plaud purchased them for the FDR American Heritage Center Museum at Union Station in Worcester.

Dr. Plaud, a forensic psychologist from Whitinsville, founded the museum two years ago with his vast collection of FDR and New Deal correspondence, documents, artifacts and memorabilia. The museum even has the sheets from Roosevelt’s deathbed.

“These are the most storied and famous images of a sitting president of the United States,” Dr. Plaud said on a recent afternoon at the museum as he held up the third in the series of Shoumatoff’s watercolors. “When you think about it, this is the last finished portrait of FDR.”

Dr. Plaud obtained the watercolors through a dealer who is a personal friend. He was told that the seller, who has chosen to remain anonymous, was impressed that the artwork would be going to a museum. “I think it’s a coup to get them,” Dr. Plaud said.

Dr. Plaud and museum director Cyrus D. Lipsitt have not decided where the watercolors will hang — but there will be plenty of wall space.

At the beginning of August, the museum will expand to more than three times its current size and encompass a large room with windows overlooking the concourse on the main floor of the railroad station. Indeed, the museum will take up the entire western side of the second floor and allow for more displays, as well as for classrooms and a lecture and events area. And, yes, Roosevelt did stop at Union Station several times.

The museum and Worcester officials have agreed to a one-year lease. The Worcester Redevelopment Authority will vote this month to authorize execution of the lease, according to Julie A. Jacobson, assistant city manager.

“We think it’s a great opportunity to have a museum with this quality of exhibits in a historical building,” Ms. Jacobson said. “They’ve been a great tenant, to date.”

She said that the city has been seeking commercial renters for Union Station; the museum and the city will revisit the arrangement in a year’s time.

“It provides opportunity for the museum to expand now,” Ms. Jacobson said. “They’re a destination tenant. It’s a good partnership.”

As the museum grows in size, it also broadens its reach.

Dr. Plaud will play a key role in a national celebration of the 75th anniversary of the New Deal, which will run from March 2008 to March 2009. New Deal programs unfolded between 1933 and 1943 and touched on nearly every area of life, including regulation of the banking system, the electrical grid, Social Security, public education, public health, collective bargaining by labor unions, and national parks.

Dr. Plaud is a member of an executive committee composed of representatives of organizations dedicated to Roosevelt’s legacy, among them the National New Deal Preservation Association in New Mexico; the Little White House, a national park; and the Roosevelt Institution, a student think tank that focuses on a progressive agenda.

“We are going to facilitate local groups to put on demonstration projects, go into schools, give lectures and work with the state historical preservation offices,” Dr. Plaud said. “We will help coordinate all kinds of different activities.”

He added, “A lot is under threat right now.”

For more information on the FDR museum, refer to http://www.fdrheritage.org/. For information on the New Deal celebration see http://www.newdeal75.org/ or http://www.newdeal75.com/.