Darwin Day in America contains major sections exploring: the intellectual roots of scientific materialism and social Darwinism; crime and punishment; welfare policy and eugenics; business and economics; debates over teaching evolution; sex education; and bioethics. 

The book inclues an interesting mix of intellectual history and accounts of the practical impact of those ideas on real-world debates.

The chapters documenting the pervasive impact of scientific materialism on public policy are based on extensive research in primary sources, including archival materials at the American Philosophical Society and Cal Tech.

Darwin Day in America debunks several widely held myths: 

• The myth that eugenics, “social Darwinism,” and scientific racism are simply distortions of Darwin’s theory of evolution.
• The myth that Darwin himself wasn’t concerned about the application of his theory to human society.
• The myth that eugenics was foisted on the scientific community by politicians who twisted science for their own ends. 
• The “conservative” myth that Darwinism provides important support for capitalism; and the “liberal” myth that capitalism is nothing more than Darwinian “survival of the fittest.”
• The myth that modern proponents of Darwinian evolution are metaphysically neutral on religion whereas all critics of Darwinism are fanatical religious fundamentalists.
• The myth that the sex education reformers who arose in the 1960s were simply trying to replace outdated and prudish beliefs with neutral scientific facts.
• The myth that scientists, unlike the rest of society, tend to be objective and fair-minded when they try to influence public policy.
• The myth that the current scientific consensus on any given topic “must” be right.