Mahalia Jackson's 1947 recording of "Amazing Grace" received significant radio airplay and, as her popularity grew throughout the 1950s and 1960s, she often sang it at public events including concerts at Carnegie Hall. In the 1960s, with the African American Civil Rights Movement and opposition to the Vietnam War, the song took on a political tone.

Mahalia Jackson employed "Amazing Grace" for Civil Rights marchers, writing that she used it "to give magical protection — a charm to ward off danger, an incantation to the angels of heaven to descend ... I was not sure the magic worked outside the church walls ... in the open air of Mississippi. But I wasn't taking any chances." Folk singer Judy Collins, who knew the song before she could remember learning it, witnessed Fannie Lou Hamer leading marchers in Mississippi in 1964, singing "Amazing Grace".

John Newton - a clergyman and reformed slave-trader - wrote "Amazing Grace" to illustrate a sermon on New Year's Day, 1773. The text was published in 1779 in Newton and Cowper's "Olney Hymns" but settled into relative obscurity in England. In the United States, however, "Amazing Grace" was used extensively during the Second Great Awakening in the early 19th century.

Another verse was first recorded in Harriet Beecher Stowe's immensely influential 1852 anti-slavery novel "Uncle Tom's Cabin". Three verses were emblematically sung by Tom in his hour of deepest crisis. He sings the sixth and fifth verses in that order, and Stowe included another verse that had been passed down orally in African American communities for at least 50 years.

It was originally one of between 50 and 70 verses of a song titled "Jerusalem, My Happy Home" that first appeared in a 1790 book called "A Collection of Sacred Ballads";
When we've been there ten thousand years,
Bright shining as the sun,
We've no less days to sing God's praise,
Than when we first begun.

Common meter hymns were interchangeable with a variety of tunes; more than twenty musical settings of "Amazing Grace" circulated with varying popularity until 1835 when William Walker assigned Newton's words to a traditional song named "New Britain", which was itself an amalgamation of two melodies ("Gallaher" and "St. Mary") first published in the "Columbian Harmony" by Charles H. Spilman and Benjamin Shaw (Cincinnati, 1829).

Spilman and Shaw, students at Kentucky's Centre College, compiled their tunebook both for public worship and revivals, to satisfy "the wants of the Church in her triumphal march." Most of the tunes had been previously published, but "Gallaher" and "St. Mary" had not. As neither tune is attributed and both show elements of oral transmission, scholars can only speculate that they are possibly of British origin. (Source; Wikipedia)