OXFORD, Wis. (AP) -- Former Illinois Gov. George Ryan slipped through a back gate at a rural federal prison Wednesday, avoiding any fanfare as he began serving a 6.5-year corruption sentence.

The 73-year-old Republican entered the federal correctional center about noon, Bureau of Prisons spokeswoman Felicia Ponce said, and managed to avoid a throng of media awaiting his arrival at the main entrance.

Former Gov. James Thompson, Ryan's lead attorney and longtime friend, was expected to speak outside the prison.

Ryan, who gained international acclaim for his opposition to the death penalty, has said he will fight to clear his name even while sitting in prison.

"Tomorrow I embark on a new journey in my life," the 73-year-old said Tuesday night surrounded by family and friends. "I do so with a firm faith in God and the support and faith of my family."

Ryan was convicted in April 2006 of steering big-money state contracts to friends, using state money and state workers to run his campaigns and killing an investigation of bribes paid for truck driver's licenses.

But he had remained free on bond since while attorneys took their cases to an appeals court, which twice turned down his pleas for a trial.

Ryan reported after the U.S. Supreme Court rejected his request to stay free while his case is appealed to the nation's highest court.

"But I do so with a clear conscience. And I have said since the beginning of this 10-year ordeal that I am innocent and I intend to prove that," Ryan said.