The coeditors of an "American Annals of the Deaf" special issue on deafblindness introduce readers to critical issues surrounding children and youth who are deafblind. These issues--early identification, communication, social-emotional needs, family and multicultural issues, universal design and assistive technology, transition planning, and personnel preparation--are explored further in the articles that follow. By way of introduction, the present article provides definitions of deafblindness and a discussion of the heterogeneous nature of the population. The history of the field of deafblindness is then explored in terms of three distinct population shifts, from (a) individuals of the 18th and 19th centuries who became deafblind due to illness, to (b) the influx of individuals with congenital rubella syndrome in the 1960s who had disabilities besides deafblindness, and (c) the current population of children and youth with deafblindness, which includes individuals with other complex disabilities.