BALTIMORE — At a table in the library of the Maryland Historical Society, an investigator with the National Archives pulls file folder after file folder from a cardboard box and hands them to library director Patricia Dockman Anderson. An FBI agent sits nearby.

Item No. 451: an invitation to meet Vice President Hubert Humphrey in Hawaii in 1966. Item No. 1695: a ticket stub to the 1912 Democratic National Convention. Item No. 1332: a program linked to President Abraham Lincoln's 1865 funeral.

Until recently, the documents were evidence, some of the more than 10,000 items seized in a massive theft investigation that ensnared a well-known collector of presidential memorabilia and his assistant. This week, however, they were returned to the society to become again pieces of history available to researchers.

"We're the stewards. This stuff belongs to the American people, and we're responsible for it," Anderson said. "That's why it's so gratifying to have these back. Ultimately our job is to make sure it gets from one generation to the next."

Barry Landau and his assistant, Jason Savedoff, were caught in the act of stealing documents from the historical society's library almost two years ago.

An investigation ultimately led authorities to a cache of thousands of stolen documents in Landau's New York City apartment, including documents from a who's who of American and international history: Presidents George Washington and Theodore Roosevelt, English writer Charles Dickens and German philosopher Karl Marx, scientist Isaac Newton and women's rights champion Susan B. Anthony. Both men ultimately pleaded guilty to their crimes and are serving prison sentences.

Now, officials are returning the stolen documents to their rightful owners: 24 different victims nationwide, including university libraries and historical societies in New York, Connecticut and Pennsylvania. Officials returned 21 items to the Maryland Historical Society in Baltimore on Monday.

Returning the documents has been easy, but figuring out who should get them has required some sleuthing.

The origins of a few of the most unique documents were easy to trace, either because the thieves kept records of those heists or because they were so valuable the institutions they had been stolen from knew they were missing.

But approximately 90 percent of the stolen materials are what historians refer to as "ephemera:" invitations or menus from balls and dinners, tickets to baseball's 1949 World Series, a program for a 1909 performance of the Marine Band. The items could have belonged to any of a number of collections and likely wouldn't have been cataloged. Archives are often so vast it is impossible for curators to inventory every button, ribbon and scrap of paper they oversee.

Returning the documents has been a joint effort by the FBI and the National Archives and Records Administration, the agency charged with preserving historical records and one of the victims of the theft.

Starting with a catalog of the 10,194 items they had seized, investigators searched for any telltale clues: a mark left on a piece of paper by a rusted paperclip, ink residue from one document that sat atop another for years, black paper stuck to the back of an item that suggested it had been ripped from an album.

Museums and archives provided records and answered questions. The thieves themselves also agreed to help as part of their plea deals. Even so, identifying the objects' owners wasn't an exact science.

"It's not going to be perfect," said Greg Tremaglio, a special agent with the National Archives' Office of Inspector General who worked on the document return.

But Tremaglio said investigators tried to place the documents where it made sense.

For example, the Historical Society of Pennsylvania has an extensive collection of material related to onetime U.S House Rep. and former Philadelphia Mayor J. Hampton Moore. There is a good chance that any documents addressed to him came from there.

The Maryland Historical Society, for its part, is grateful to investigators and pleased to have its materials back, Anderson said.

Like other archives affected by the thefts, the historical society has re-evaluated policies that enabled the thieves to get away with materials. It has reconfigured seating to make it easier for librarians to see patrons and instituted more rigorous screenings of guests leaving the library.

On Monday, Anderson studied the objects as investigator Mitch Yockelson handed them over and FBI agent Matt Kazlauskas used the item catalog to explain why certain documents were believed to be the society's. Seven of the items were tickets to the U.S. Senate's 1868 impeachment trial of President Andrew Johnson.

Anderson turned over a white ticket from May 26, the day senators failed to convict Johnson by a single vote. On the back were hash marks, as if someone had been tallying votes.

"Isn't that cool," she said.

On the back of other items were small pencil markings made by the thieves. A few said "W2," short for a nickname the thieves gave themselves: "weasel 1" and "weasel 2." Anderson said those marks are now important, too.

"It's part of the documents' history," she said.

___

Follow Jessica Gresko on Twitter: http://twitter.com/jessicagresko

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