Jesse Jackson Jr. has resigned from Congress just weeks after winning reelection for a ninth term.

Jackson Jr. has been in treatment for bipolar disorder since June. The timing of his treatment coincides with an FBI investigation into misuse of campaign funds which also reportedly began in June.

The FBI has been looking into claims that Jackson Jr. allegedly used $100,000 in campaign funds to decorate his Washington D.C. home and also purchased a $40,000 Rolex watch for "a female friend."

Days after his reelection, reports revealed that Jackson Jr. had hired attorney Dan Webb to work out a plea agreement with the Department of Justice. Though voters didn't know it when they went to the polls, the pleas deal negotiations had supposedly been taking place "for months" behind the scenes. The possible deal was said to include jail time and to require Jackson Jr.'s resignation from Congress.

Even before the FBI investigation, Jackson Jr. was being investigated by the House Ethics Committee for his alleged attempts to raise money for disgraced former Governor Rod Blagojevich in an attempt to get himself appointed to the US Senate. Jackson denied involvement in the Blagojeich scandal. 

His resignation puts an end to the House investigation.