Fair Deal in the context of Lyndon Johnson

Modern liberalism, often referred to simply as liberalism, is the dominant ideological variant of liberalism in the United States. It is most synonymous with the ideology of social liberalism, which is a variant of liberalism that moves beyond classical liberalism to account for poverty, seeking a balance between civil liberty and social equality via a social safety net. U.S. modern liberalism also takes inspiration from cultural liberalism and progressivism, and some (but not all) modern liberals explicitly identify with the contemporary U.S. progressive movement. Writing in 1993, American academic writer Ian Adams argued all major U.S. parties up to that point were "liberal and always have been. Essentially they espouse classical liberalism, that is a form of democratized Whig constitutionalism plus the free market. The point of difference comes with the influence of social liberalism."

Economically, modern liberalism accepts a role for government to protect against market failures, protect competition and prevent corporate monopolies, and supports labor rights. Its fiscal policy supports sufficient funding for a social safety net, while simultaneously promoting income-proportional tax reform policies to reduce deficits. It calls for active government involvement in other social and economic matters such as reducing economic inequality, expanding access to education and healthcare, and protection of the shared natural environment, in large part on the contention that advances in those areas create a thriving economy in the long run. Modern liberalism was formed in the 20th century in response to the Great Depression. Major examples of modern liberal policy programs include the New Deal, the Fair Deal, the New Frontier, the Great Society, the Affordable Care Act, and the Build Back Better Plan.

Harlow Shapley (November 2, 1885 – October 20, 1972) was an American astronomer, who served as head of the Harvard College Observatory from 1921–1952, and political activist during the latter New Deal and Fair Deal.

Shapley used Cepheid variable stars to estimate the size of the Milky Way Galaxy and the Sun's position within it. In 1953 he proposed his "liquid water belt" theory, a concept now known as a habitable zone.

The American Housing Act of 1949 (Pub. L. 81–171) was a landmark, sweeping expansion of the federal role in mortgage insurance and issuance and the construction of public housing. It was part of President Harry Truman's program of domestic legislation, the Fair Deal.