Millard Fuller

He believed in "sweat equity" and the "theology of enough." It took a while, however, for Millard Fuller, who died on Feb. 3 at age 74, to develop that selfless philosophy into Habitat for Humanity, which he co-founded with his wife Linda.

During his law-school days, Fuller sold everything from rat poison to cookbooks with classmate Morris Dees, who later co-founded the Southern Poverty Law Center. Although the pair raked in the dough--both became millionaires by age 29--Fuller's obsession with amassing wealth pushed Linda away; in the '60s she left with their two young children and considered divorce.

During their eventual reconciliation, the couple decided to sell their possessions, donate the proceeds and move to Koinonia Farm, a Christian commune in Americus, Ga. It was there that they conceived their first ideas about building homes with no-interest mortgages for the poor. The family packed up for Mbandaka, Zaïre (now Democratic Republic of Congo), in 1973 to develop a program there.

On returning to Americus in 1976, the couple founded Habitat for Humanity, which with the help of volunteers and future occupants has built nearly 1.5 million no-interest homes worldwide. Fuller separated from Habitat in 2005, forming the similarly tasked Fuller Center for Housing.

Long supported by public figures like former President Jimmy Carter, Fuller was awarded the Presidential Medal of Freedom in 1996 by Bill Clinton for his commitment to giving people a decent place to live. As Fuller once said, "There are sufficient resources in the world for the needs of everybody but not enough for the greed of even a significant minority."