Writing at Patently-O, Dennis Crouch corrects the common story that H.N. Wadsworth received the first American toothbrush patent in 1857. Patent Office records and a Connecticut state table point to an earlier grant: Philos Blake of New Haven, Connecticut, patented a "Folding, Pocket Tooth Brush" on March 8, 1830. The original was lost in the 1836 Patent Office fire, but the Journal of the Franklin Institute preserved the listing and Blake's claim.
Blake's claim is notable for its structure. He disclaimed the known ideas of a portable toothbrush in a case and a case that doubles as a handle, then claimed only his improvement: connecting the brush to its case by a pivot or revolving joint. Crouch notes that this is the logic of a Jepson claim, nearly ninety years before Ex parte Jepson. The journal's editor was skeptical of the business case, worrying that toothbrushes made this way would be too expensive for widespread use.
Crouch also flags a smaller discrepancy: the Library of Congress dates Wadsworth's patent November 7, 1857, while the patent itself says November 17. The full post continues with an analysis of roughly 7,000 toothbrush patents since 1976, but the key historical correction is that Blake beat Wadsworth by 27 years—even if his patent record did not survive the fire.