November 1998 — University of Wisconsin scientists publish their discovery of human embryonic stem cells.
August 23, 2000 — National Institutes of Health issues final guidelines for funding stem cell research. Former President Bill Clinton supports the guidelines, while Presidential candidate George W. Bush opposes federal funding of such research.
February 2001 — President Bush requests a review on the issue and puts federal funding for stem cell research projects on hold.
July 18, 2001 — Senator Bill Frist (R-Tennessee), a Bush ally, joins anti-abortion Senator Orrin Hatch (R-Utah) in backing limited funding for stem cell research.
July 29, 2001 — House Speaker Dennis Hastert (R-Illinois) joins other GOP House leaders in opposing funding for research.
July 31, 2001 — House votes to ban human cloning. Opponents of the ban say it signals Bush’s intention to limit scientific research.
August 9, 2001 — Bush announces his decision to limit funding to existing 60 lines of stem cell research.