Sassafras is the traditional flavoring for root beer and thickening agent (filé) for Creole gumbo.
Root tea of sassafras and its close relative, spicebush, has long been used as a folk remedy for a variety of ailments (for example, for "thinning" or "purifying" the blood). There are many folklore beliefs about what roots are the best, such as a preference for "young, red" roots over "larger, white" ones; also, that it is not worth harvesting roots until after February 14.
European explorers in the 1500s and 1600s thought it was a cure-all, and soon Europeans were paying high prices for its import ― but this was back when virtually any aromatic plant was considered curative for almost any ailment.
Since then, science has cast doubt on its efficacy and has shown that safrole, an oil in sassafras, causes cancer in laboratory animals. The FDA has banned use sassafras tea, roots, and oil in commercially mass-produced foods and drugs.
The celebrated folklorist Vance Randolph reported that Ozark oldtimers believed that a sassafras "bat" had to be used when stirring to render lard, as it was supposed to flavor the lard and keep it from turning rancid. Many people still maintain that sassafras wood is the preferred stirrer for the long cooking process of making apple butter.
Randolph reported several other Ozark sassafras superstitions. For example, burning sassafras (which, he notes, makes a high-quality charcoal) was believed to cause the death of one's mother, so no one would burn it or even move it to the kiln, unless his mother was already dead. An old Ozark saying went, "the Devil sits a-straddle of the roof when sassafras pops in the fireplace."
Finally, Randolph also reported that some Ozarkers used to believe that sassafras trees "somehow" sprouted "from grub worms." (Maybe this idea came from its suckering habit and its being the host of butterfly caterpillars?)
The wood has many uses, too. In the state of Louisiana, the floors in the cabins of enslaved people were often made of sassafras wood, as the scented wood was believed to repel bedbugs. Sassafras used to be popular for making bedsteads, for the same reason.
A pleasant tree in cultivation, the leaves of sassafras can be spectacular in autumn. The large taproot makes it difficult to transplant, and sassafras trees send out root suckers, creating a multistemmed shrub or colony if the suckers are not removed. Thus it can be a beautiful medium-sized specimen tree or a shrubby screen if allowed to colonize.