This article deals with immigration from Earth to other planets. For further predictions for immigration in the future, see this.
The first immigrants from USA left Earth for Venus in 1946, in the beginning of Cold War, when American communists founded the People's Republic of New America on the continent of Chelemice.
Twenty years later, during the Vietnam War, the immigration rate to Venus was already ~100 U.S. citizens/year. After the war, it was only 40/year.
Over time and better technology, the immigration reached 500/year in 1999. Bill Gates conquered Gatesland the next year. Iraq War made the immigration peak into 4000/year in 2003.