Terms of the deal weren't announced, but ESPN reported it was worth $52 million, including an $8 million signing bonus and annual salaries of $11 million per year.
Jackson, 29, compiled a 10-11 record with a 4.03 earned run average last season with Washington.
The 10-year veteran boasts a 70-71 career mark with a 4.40 ERA and tossed a 150-pitch no-hitter in 2010 while with the Arizona Diamondbacks.
Jackson has also pitched for the Los Angeles Dodgers, Tampa Bay, Detroit, the Chicago White Sox and St. Louis.
Notable deaths of 2014 [PHOTOS]