I know that Louisiana and California aren't the only game in town when it comes to Loustalot landings on American soil, but it does seem that the two main branches landed there and prospered (tho I gotta say, procreation seems at lower levels than in the past, IYKWIM. . ) somewhat, at least in the early years of the 20th century. .
I've found a record at Ancestry from the New Orleans passenger lists (didn't I post that before? gotta check) of a Vincent Loustalot, b.1861 in France who departed from Pau, Basse-Pyrenees and arrived in New Orleans in around 1876. .that's earlier than the crowd who eventually populated California (who were being born at that time) and claimed origination at Pau (at least my husband's family) but who may have actually lived up the road in the town of Lurbe in that region. .