A presidential memorabilia collector who has acknowledged stealing thousands of rare and valuable documents from historical societies and archives nationwide was sentenced Wednesday to seven years in prison.

Barry Landau was caught stealing documents from the Maryland Historical Society in July 2011. An investigation concluded the 64-year-old New York City resident stole at least 6,500 items worth more than $1 million from archives around the country.

A number of the stolen documents are more than 100 years old and some are worth more than $100,000. They include copies of speeches President Franklin D. Roosevelt read from during his three inaugurations, a land grant signed by President Abraham Lincoln in 1861 and letters written by scientist Isaac Newton, Confederate Gen. Robert E. Lee and novelist Charles Dickens.

But the stolen artifacts also include smaller items such as photographs of President Calvin Coolidge and World Series baseball tickets from 1949. The earliest document dates from 1479.

"Barry Landau, simply put, tried to steal history for his personal benefit and financial gain. His actions breached a trust once enjoyed, but now lost, between researcher and museum," prosecutors wrote in a document submitted to the court before Landau's sentencing.

Prosecutors recommended a nine-year sentence and said it is likely Landau had stolen items as early as 2003.

Landau told the judge in a brief statement before he was sentenced that he was "deeply ashamed" and "embarrassed" by his actions. Standing with the assistance of a cane, he said he hoped one day to "redeem himself."

In a plea agreement signed in February, Landau acknowledged that he and his now 25-year-old assistant Jason Savedoff visited historical archives in order to steal. They would distract staff, sometimes with cookies and donuts, and simultaneously stuff valuable documents into secret pockets in their clothing. On Wednesday, prosecutors displayed a tan trench coat and navy blazer in court, both of them specially altered by Landau's tailor to contain deep pockets.

The pair, who referred to each other as "weasel 1" and "weasel 2," attempted to cover up the thefts by removing card catalog listings for the items and using sandpaper and other methods to remove museum markings, a process they called "performing surgery."

On Wednesday, prosecutor James Warwick attempted to paint Landau as the leader of the thefts and called Savedoff an "amateur." But one of Landau's attorneys, Andrew White, said it was Savedoff who pushed Landau to steal more valuable documents after the pair met in 2010.

Savedoff has pleaded guilty to theft of major artwork and conspiracy to commit theft of major artwork. No sentencing date has been set.

The parties also disagreed about the extent of the thefts. Prosecutors said it's possible that the full extent of the pair's thefts will never be known, but Landau's attorney said every document has been recovered, including about $46,000 in documents that were stolen and then sold.

Landau has acknowledged stealing documents from at least five institutions in addition to the Maryland Historical Society. They are the Historical Society of Pennsylvania, the Connecticut Historical Society, the University of Vermont, the New York Historical Society and the Franklin D. Roosevelt Presidential library in Hyde Park, N.Y.

Court documents also suggest he also stole from the Culinary Arts Museum at Johnson & Wales University in Providence, R.I., as well as from former Clinton White House Secretary Betty Currie, who Landau stayed with as a guest in 2010. Over 250 items belonging to Currie were found at Landau's residence.

Landau is expected to turn himself in to prison authorities in August, and when he gets out of prison, he will spend three years on probation. As a special condition of his release, however, he won't be able to go to an archive or museum without the approval of his probation officer.