The data on telephones were obtained from answers to long-form questionnaire Item 41, which was asked on a sample basis at occupied housing units. Households with telephone service have a telephone in working order and are able to make and receive calls. Households whose service has been discontinued for nonpayment or other reasons are not counted as having telephone service available.

In Census 2000, the telephone question emphasizes the availability of service in the house, apartment, or mobile home. Data on telephone service are needed because an individual can own a telephone but have no service to make or receive calls. In 1980 and 1990, respondents were asked about the presence of a telephone in the housing unit. In 1960 and 1970, a unit was classified as having a telephone available if there was a telephone number on which the occupants of the unit could be reached. The telephone could have been in another unit, in a common hall, or outside the building.

A person having origins in any of the original peoples of Europe, the Middle East, or North Africa. It includes people who indicate their race as "White" or report entries such as Irish, German, Italian, Lebanese, Near Easterner, Arab, or Polish.