He went into medical practice at
Jackson,
East Feliciana Parish,
Louisiana and continued to pursue an interest in the
natural sciences. In 1838, he published a study of a submerged forest he discovered near
Port Hudson,
East Baton Rouge Parish, Louisiana. where he was appointed
dean in 1845. In 1844, he published a study on the habit of dirt eating among
Negro slaves, and he published several other significant studies. He was a leading proponent of research into disease transportability and transmission as related to importation of disease and outbreak of
epidemics. He joined the faculty of the
Medical College of Louisiana as Professor of
Botany and
Geology, and from 1845 to 1846 he was
Dean of the
Tulane University School of Medicine. From 1846 through 1848, he was editor of the
New Orleans Medical and Surgical Journal. His botanical collections were published posthumously and several plants were named in his honor, including the rare flowering California Bush Anemone,
Carpenteria californica, which was "named in honour of Professor William M. Carpenter (1811-48), a
physician from Louisiana, by its discoverer, Major General
John Charles Fremont, who collected it on one of his four journeys of exploration in the extreme west of the United States between 1842 and 1848."
Carpenter's Groundcherry (
Physalis carpenteri Riddell, 1853
ex Rydberg, 1896), a plant in the
nightshade family indigenous to Louisiana, and Carpenter's
Oak,
Quercus carpenteri Riddell, 1853, also indigenous to Louisiana, were named in his honor by fellow
naturalist John Leonard Riddell. ==Personal==