Evangelicalism is a broad Protestant movement defined by a belief in the necessity of a personal conversion experience ('being born again').

It also emphasizes the authority of the Bible, the death and resurrection of Jesus Christ, and the importance of evangelism (sharing the faith).

Its roots in America lie in the Great Awakenings and the fundamentalist movement of the early 20th century.

The post-World War II era saw the rise of prominent evangelists like Billy Graham, who used mass media like radio and television crusades to reach a huge audience.

A network of evangelical churches, colleges, and organizations grew rapidly during this period.

In the late 1970s, a new political movement known as the 'Religious Right' or 'New Christian Right' emerged.

This movement, led by figures like Jerry Falwell, mobilized conservative evangelical voters to become a powerful force in politics.

The Religious Right focused on social issues, such as opposition to abortion and support for prayer in schools.

It became a key component of the Republican Party coalition and was instrumental in the election of Ronald Reagan in 1980.

Evangelicalism remains a major social, cultural, and political force in the United States today.