For more than 2000 years all nonhuman animals have been viewed as legal things, entities that lack the capacity for any legal right. As a result they are routinely killed, otherwise exploited, and continually driven to extinction in their tens of billions each year. It is personhood alone that gives an entity the capacity for legal rights; personhood alone allows one's most fundamental interests to be protected. Without legal personhood an entity has no legal rights, while every thing is naked to the power of persons. In short, persons count in law, things don't. Persons are visible to civil law. Things aren't. Persons are the masters of things, things are the slaves of masters. My work and the work of the Nonhuman Rights Project is, and has been, through litigation and legislation, to require humankind to greatly expand the number of entities recognized as legal persons and to include as many species of nonhuman animals and to recognize as many of their legal rights as justice demands.