The Fourteenth Amendment to the Constitution, ratified in 1868, sought to protect the rights of the newly freed slaves; but its first important test did not arise until five years later. When it did, it centered on a vitriolic dispute among the white butchers of mid-Reconstruction New Orleans.

The rough-and-tumble world of nineteenth-century New Orleans was a sanitation nightmare, with the city's many slaughterhouses dumping animal remains into neighboring backwaters. When Louisiana finally authorized a monopoly slaughterhouse to bring about sanitation reform, many butchers felt...