Animal identification has been one of the most contentious issues for the last decade in the livestock industry. More specifically, at issue is the idea of a government-sponsored identification system, although it is unclear that an identification system forced on the industry by the market would be any more popular. Rancor over the issue has set livestock groups at odds over the merits of establishing such a framework; it has highlighted differences between species, within species, and by size and scale of agriculture. Given its politically sensitive nature, many groups without a tie to agriculture have been drawn in to lobby on the issue. This article examines the U.S. experience with the development of an animal identification system.