The city of Bethlehem goes back over 200 years. It was founded by the Moravians, a religious order, who, amongst other things, established Moravian College. During the Industrial Revolution, it was a center of iron and steel production, which, along with the coal and rail tie-ins, made some people quite wealthy.
Architecturally, the Garden District of New Orleans really has nothing over the area of North Bethlehem just east of Moravian College and the downtown district. Here's just a few houses in the area. Keep in mind Bethlehem also lacks the sweltering, humid climate of New Orleans (although it does have some pretty ugly winter days on occasion).