This document provides an annotated timeline of key events in the development of U.S. patent law as it relates to genetics from 1474 to 2000. Some of the major events included are the first patent statute passed by the U.S. Congress in 1790, Louis Pasteur being awarded the first patent on a microorganism in 1873, the Supreme Court ruling in 1980 that living matter produced through genetic engineering can be patented, and patents being awarded in Britain in 2000 covering methods of cloning non-human animals and human cell lines. The timeline traces the evolution of patent law as new technologies emerged to encompass various life forms including microorganisms, plants, animals and human cell lines and genetic material.