On 17 December 1862, almost halfway into the Civil War, the Union general Ulysses S Grant ordered the expulsion of all Jews from the territory under his command in the South.

The order would ignite fierce condemnation, terrify and infuriate the 150,000 Jews living in America and cast a long shadow over Grant's presidency and historical reputation.

The inglorious and little-known moment in American history was one that would haunt a national hero throughout his life.

Jonathan D Sarna tells this story in his new book, When General Grant Expelled the Jews. He explains how, once elected to the highest office in the US, President Grant sought to make amends.

Produced by the BBC's Jane Little and Bill McKenna