Subject-Matter Index of Patents for Inventions issued by the United States Patent Office from 1790 to 1873, inclusive: Compiled & published under the Direction of M. D. Leggett, Commissioner of Patents

Commissioned under the direction of M.D. Leggett, who served as the United States Commissioner of Patents from 1871 to 1874, this index was compiled to address the increasing administrative burden of the Patent Office during the post-Civil War era. As industrial innovation accelerated, the government sought to organize the massive backlog of grants recorded since the establishment of the patent system in 1790. This specific compilation served as a foundational reference tool for attorneys, engineers, and researchers by categorizing the broad spectrum of American mechanical and technological advancements into accessible subject-matter headings.

The publication reflects the meticulous bureaucratic standardization of the late 19th century, serving as both a legal record and a primary source for the history of American invention. The design is characteristic of government printing office production of the period, prioritizing functional typography and logical classification schemes over aesthetic ornamentation. Upon its release, it was highly regarded within legal and industrial circles for its utility, as it bridged the gap between the chaotic early years of patent registration and the more structured regulatory environment that characterized the Gilded Age.