Jesse Jackson Jr. Resigns from Congress, citing health issues; Jackson being investigated for alleged campaign fund misuse

A stunning development has taken place in the U.S. House of Representatives as Rep. Jesse Jackson, D-Illinois, resigned from his congressional post Wednesday, amid health problems and reported investigations into his use of campaign funds.

"My health issues and treatment regimen have become incompatible with service in the House of Representatives. Therefore, it is with great regret that I hereby resign ... effective today, in order to focus on restoring my health," the Chicago Democrat said in a two-page letter to U.S. House Speaker John Boehner, according to Reuters.

The son of civil rights leader Jesse Jackson and a one-time rising star in the Democratic Party, Jackson also acknowledged in the letter to Boehner that he was being investigated by federal authorities related to allegations of misused campaign funding on his behalf.

"I am aware of the ongoing federal investigation into my activities and I am doing my best to address the situation responsibly, cooperate with the investigators and accept responsibility for my mistakes, for they are my mistakes and mine alone," Jackson wrote.

When asked by the Washington Post, Justice Department officials would not say whether the resignation was connected to developments in the investigation or comment on the inquiry, except to say that it is ongoing.

Jackson, whose last recorded vote was on June 8, has been absent from office for roughly six months and underwent multiple visits at the Mayo Clinic in Minnesota as he battled depression and bipolar disorder. His last recorded press statement prior to this week came on June 18, when he blasted GOP congressional leaders for delaying votes crucial to helping construction workers and students dealing with college loans.

However, Jackson's decision to step down is not expected to cause major changes in the political balance of power of the U.S. House, still maintained by a Republican majority. Voters in Jackson's Illinois district will now have to hold a special election to fill the vacancy.

Illinois Governor Pat Quinn told Reuters that he would attempt to set a date for a special election within five days.

"We know that Congressman Jackson is confronting health challenges, and our thoughts and prayers are with him and his family during this difficult time," Quinn said.