Read Jackson's resignation letter here: JACKSON'S LETTER TO BOEHNER
It has been a long journey for Jesse Jackson Jr.
It's one that began really in 2008 -- when Jackson first came under scrutiny for alleged activities involving Rod Blagojevich and the sale of Barack Obama's vacant U.S. Senate seat.
Jackson was not charged then though Blagojevich's brother went to congress asking that the South Shore Democrat come under greater scrutiny for a scheme that sent the former governor to prison for 14 years.
Ultimately, it was other behavior that caught the attention of federal investigators years later and would lead to his downfall.
The Sun-Times first revealed the new probe on Oct. 12: Read the story here.