 There are many categories or groups into which people can place themselves, and be placed, on the basis of their varying characteristics. The salience and appeal of these categories depend on social and historical context as well as individual preferences and values. Identity and identity politics become important as members of historically excluded groups challenge their status and work for inclusion. Many women gained a sense of group identity in opposing laws that limited voting and other political rights to men; racial identities have been forged in the fight against segregation. Although people with disabilities are not always understood as sharing an identity, their awareness of membership in an oppressed group has been shaped by exclusionary laws and customs, from “ugly laws” prohibiting people with physical deformities from appearing in public to the state-sponsored involuntary sterilization of “mental defectives”. A sense of group identity has been further encouraged by welfare, social security and other laws that place people with various disabilities in a single category, even if they define that category in different ways.