In 1990, Teresa Heinz met Senator Kerry at an Earth Day rally. This was the only reported time the two met before Senator Heinz died in a plane crash on April 4, 1991. In 1992, Teresa Heinz met Kerry again, this time at the Earth Summit in Rio de Janeiro, Brazil. Heinz was a member of a State Department delegation appointed by then-President George H. W. Bush. The two began courting in 1993 and were married May 26, 1995, in Nantucket, Massachusetts. Choosing to remain registered as a Republican until John Kerry's presidential bid in 2004, Heinz retained the name Teresa Heinz. In May 2004, she said:
Heinz has contributed to the environmental movement through many programs and outreach efforts. In 1990, she co-founded the Alliance to End Childhood Lead Poisoning (later known as the Alliance for Healthy Homes, it has since merged with the National Center for Healthy Housing), through the first environmental grant of the Vira I. Heinz Endowment. In 1992, she was a Delegate to the Earth Summit, representing Non-Governmental Organizations.