Hyde Park, N.Y.

Since June 1941, when President Franklin D. Roosevelt presented his home as a gift to the American people, Hyde Park has stood as the first presidential library and museum. Now, this most senior of our presidential libraries is also the freshest. After a three-year renovation, the Franklin D. Roosevelt Library and Museum has unveiled a redesigned permanent exhibition, an expansion to 12,000 from 8,000 square feet that reinvigorates Roosevelt's legacy for visitors.

Franklin D. Roosevelt Library Archives

Branded as a "New Deal for a New Generation," the overhauled library and museum has been transformed from a dated gallery of trophy cases into a cutting-edge, high-tech facility—without compromising the breadth of Roosevelt the politician, the humanitarian, the citizen of a radically evolving world. Its predecessor, while showcasing many artifacts through the years, had grown stale. Moreover, it lacked organization and direction for museum-goers, failing to utilize efficiently its generous space.

The curators behind the new library have corrected these problems. (Happily left in place, however, is Roosevelt's home study, just where it was in his Hyde Park days.) The meticulously mapped redesign has a sound chronological sequence of exhibits, employing dynamic colors and original photos that are enlarged and turned into panels of disparate sizes and shapes. All of the presidential memorabilia and historical documents remain on display.

Roosevelt's birthplace, an estate that commands beautiful views of the Hudson and of Dutchess County's pastoral countryside, is a constant reminder of his privileged upbringing. But upon entering the revamped library, class distinctions are left behind in favor of a united America. A first luminous wall of letters to President Roosevelt, bordering a photo of a smiling, sanguine commander in chief, gives voice to Americans of the era.

"The test of our progress is not whether we add more to the abundance of those who have much, it is whether we provide enough for those who have too little," reads an excerpt from Roosevelt's January 1937 inaugural address.

Roosevelt as the activist president who changed the way government operates is front-and-center. The library inventively captures New Deal programs as a kind of construction site of financial reforms rebuilding the country, brick by brick. While it boldly projects Roosevelt's political ideology, including his conviction about the merits of government, it delivers facts—like the steep decline but then increase in unemployment—that will fuel a visitor's own appraisal of the policies enacted.

Creative technologies enhance the presentations. The first in a trail of interactive features is a digital family scrapbook linking FDR's family lineage to that of our earlier president Theodore Roosevelt. Visitors can sit in reconstructed 1940s dining rooms and tap to listen to radio broadcasts of Fireside Chats. There are also stations where museum-goers can look up names associated with the Roosevelt years.

Multimedia presentations "confront" debates of the age, such as the effectiveness of New Deal reforms, with digitally accessible primary source documents—as well as possible moral breaches, such as Roosevelt's internment of Japanese-Americans and his delayed response to the Holocaust and to Jews seeking political refuge.

A digital portal headlined "A New Deal for African Americans?" asks whether Roosevelt's reforms truly extended to people of color. In one document, Roosevelt aide Harry Hopkins, who managed the Works Progress Administration, promises the agency will not discriminate against African-American job-seekers. But it is not until 1941, when first lady Eleanor Roosevelt pens a "MEMO FOR THE PRESIDENT," that Roosevelt is implored to hire "a Negro in a position who can actually confer with the President on problems that are pertinent to Negroes."

The war is covered comprehensively. There's a timeline; original posters promoting the purchase of war bonds; and an impressive re-creation of the president's top-secret map-room, from which he ran the war. The new museum is no less focused on documents, including Roosevelt's handwritten list of countries to be included in the United Nations and various declassified communiqués. While the original papers are available only in the library's depository, the curators replicate exact markings of the papers, including penciled edits and crooked edges. In his speech to Congress after the attack on Pearl Harbor, onlookers can see Roosevelt's own replacement of "in world history" to "in infamy" in referring to Dec. 7, 1941.

One of the most important assets of the library is added context. Few modern-day visitors have experienced the mass unemployment and sheer panic of the Great Depression. The introductory video montage dramatically imagines viewers on a bread line in that most dire of times.

In the political realm, there is also useful background on the Democratic majorities that made the New Deal achievable. Each of the four elections is marked with a huge electoral map, tallies of party gains and losses in Congress and other salient details from each cycle, such as a rising number of women in the workplace.

The library makes a compelling case that Mrs. Roosevelt was "a revolutionary partner" in the presidency, weaving her into FDR's unprecedented four terms, through wartime reels of official visits overseas as well as her internal White House messages and nationally syndicated columns.

Unfortunately, the postrenovation library has only modest coverage of FDR's New York governorship and earlier career. There is also a missed opportunity to explore fully the psychological effects of Roosevelt's affliction with polio. A brief video explains how he summoned the strength to push forward against the effects of the disease even as it paralyzed his body and led to his deteriorating health.

The final gallery underscores the exhibit's populist theme. Surrounding the actual Oval Office desk where Roosevelt signed landmark New Deal legislation and declarations of war against Japan and Germany are crystal blue and white plaques delineating the "Four Freedoms" from the president's famous wartime address: freedom of speech and expression, of worship, from want and from fear.

It is a fitting ending to a beautifully updated history of Roosevelt. Among the displayed letters to the president, Vincent Dwyer of Pittsburgh writes: "I think your radio talks weld the whole country into one unified whole . . . Thank you for taking the trouble to tell me about things."

Recounted in these words, FDR's humanity and imagination—the crux of his connection to the American people—imbue the revitalized library and museum.

Mr. Heffner is a writer in Providence, R.I.