Bob Dole was quite the politician. Turns out he was a pack rat, too.

The former senator’s 4,000 boxes of papers now in the archive section of the Dole Institute of Politics make it the largest collection of political papers outside the nation’s presidential libraries.

Four thousand boxes is a huge amount.

Former Sen. Nancy Kassebaum Baker’s papers, now in the Kansas State Historical Society’s archive in Topeka, fill about 800 boxes.

The Dole archive will be 60 percent larger than the collection of former senator and vice president Hubert Humphrey’s papers at the Minnesota Historical Society; six times larger than former Speaker of the U.S. House of Representatives Thomas “Tip” O’Neill’s.

“That’s an enormous amount of paper,” said David Horn, who oversees the O’Neill collection in the Burns Library at Boston College.

The 4,000-box figure may not hold up over time, Horn said, noting that O’Neill’s papers once filled about 1,100 boxes. But after duplicate copies, empty envelopes and irrelevant entries were removed, the number dropped to about 600.

Also, Burns said, O’Neill did not save every letter ever sent to him by a constituent. Dole did.

Kristen Nyitray, who oversees former U.S. Sen. Jacob Javits’ archive at the State University of New York at Stony Brook, said it was difficult to compare archives because some have moved away from storing everything on paper.

“The Javits collection takes up about 1,200 cubic feet, but a lot of the correspondence has been put on microfilm to save space,” she said.

Still, she said, the Javits collection is unlikely to exceed the Dole papers’ quantity. “Ours is an average-size collection,” she said.

According to the U.S. Records and Archives Administration, more than 600 senators’ and representatives’ papers are stored in archives. Most are in university libraries.

There are 10 presidential libraries, including the Dwight D. Eisenhower Presidential Library & Museum in Abilene and the Harry S. Truman Presidential Library and Museum in Independence, Mo.

The Kansas State Historical Society’s archive includes the papers of 70 Kansas congressmen, making it one of the largest collections in the nation.

Matt Veatch, assistant director of the library and archive divisions at the Kansas State Historical Society, said Dole’s 4,000 boxes could become the norm.

“Today’s office technologies — e-mails, laser copiers, fax machines — have created an explosion in the number of copies,” Veatch said. “They’re not supposed to — they’re supposed to cut paper costs. But it’s too easy; all you have to do to make a copy is punch a button.”

Veatch said archivists were exploring ways to store more documents on computers.

Besides his papers, the Dole collection includes 25,000 photographs, posters and other campaign materials.

Staff writer Terry Rombeck contributed to this report.