WASHINGTON (AP) — Rep. Aaron Schock, caught in a spending scandal over expenses that included decorating his office in the style of "Downton Abbey," said Thursday he was leaving Congress with sadness and humility and vowed to work "tirelessly" to make amends to constituents and others he has let down.

In a farewell speech, the Republican from Illinois said his departure from Congress "is not the end of the story, but rather the beginning of a new chapter" in his life.

Schock, 33, announced his resignation March 17 following a monthlong cascade of revelations about his business deals and lavish spending on everything from overseas travel to office decor in the style of the hit British show "Downton Abbey."

The U.S. Justice Department is investigating Schock's congressional expenses and business deals, and FBI agents have begun issuing subpoenas to witnesses, a person familiar with the case told The Associated Press.

Schock, whose last day in office is Tuesday, referred indirectly to the investigation, saying that like others before him, he faces adversity.

Schock voted for the final time Thursday as Congress prepares for a two-week recess.

"I believe that through life's struggles we learn from our mistakes," Schock said. "I know that God has a plan for my life."