We are faced with the increasing ability to modify our genomes through genetic enhancement. Soon we may be able to use genetic enhancement to increase our physical abilities, as well as be able to choose traits and characteristics for our children, with great implications for the entire species. When faced with having a baby with a fatal bone marrow disorder or a damaged heart, most prospective parents would try to avoid the problem. Increasingly they can, by screening embryos in the lab and choosing one most likely to be healthy—in other words, free of gene mutations known to cause disease. Genetic choices may offer a world of new possibilities for our children. But a look back at the eugenics movement, popular in the United States roughly a century ago, reveals the dangers of trying to control the genetic characteristics of future generations.