Over six decades have passed since the completion of Moser and Blum’s treatment of the ants of Louisiana. This research represents a significant contribution and update to their work. I report the first-ever comprehensive assessment of the Louisiana formicid fauna. More than 100 species from 38 genera and 8 subfamilies are covered. This fuanistic survey gives valuable data in regards to biodiversity and macro and microhabitat selection of ant species. The results indicate that at least one species no longer occurs in the state, and a number of species have their ranges reduced. This study also provides new state records. Qualitative and quantitative methods provide new evidence for the mechanisms underlying species current biogeography in the state.