This book examines the Know Nothing party in Louisiana. In the early 1850s, the Whig party disintegrated. Several third party movements appeared in the country. Know Nothings seemed to have a strong chance of replacing the Whig party and by 1854 the Know Nothings appeared throughout the United States. This book examines Louisiana because one feature of the Know Nothings, or American party as it was sometimes called, was its anti-foreign and anti-Catholic prejudice. Louisiana, particularly, South Louisiana had a large Roman Catholic population. The book seeks to address whether this feature hurt the party. The book also examines how northern Know Nothings, many of whom were anti-slavery, affected the party’s success in the South. Additionally, early studies of the Know Nothing party in Louisiana argue the party was made up of old Whigs and that traditionally, the party was seen as consisting of older, large slaveholding planters or town businessmen and lawyers connected to the slave-holding interests. This book concludes that Know Nothingism was unique in Louisiana; who actually were Know Nothings does not meet the traditional historical view for the state and the book concludes that the anti-Roman Catholic feature did not preclude South Louisiana slave-holding Catholics from belonging to the party. Louisiana Know Nothings did have difficulty because of the anti-Catholic feature, but it did not prevent Catholics from belonging. Northern Know Nothings’ abolitionism did cause problems for Louisiana Know Nothings, but the election outcomes in the 1850s demonstrated that Union and conservatism was strong in the state.