This report presents detailed information on the marital status and living arrangements of the noninstitutional population of the United States by age, sex, race, and Spanish origin. The text of this report compares the mid-decade census estimates based on the March, 1985 "Current Population Survey" with the survey data from 1980, 1970, and 1960. The report concludes that many changes in marital status and living arrangements have occurred over the last few decades. Changes in marital status include postponement of the first marriage; a growing proportion of never-married persons; and the growth of the "singles" population due to divorce and separation. Changes in living arrangements include increasing numbers of children who live in single-parent situations, of young adults who live with their parents, of persons who live alone, and of adults who reside in unmarried couple households. Highlights of the report are: during the 1980s, the proportion of never married women, aged 20 to 24, has been the largest ever recorded; there were 119 unmarried men aged 25 to 34 for every 100 women aged 25 to 34 in 1985; between 1970 and 1985 the divorce ratio rose from 47 to 128 divorced persons per 1,000 married persons with spouse present; and 23 percent of children under 18 lived with one parent in 1985, compared with 9 percent in 1960. In addition, 60 percent of men and 48 percent of women, aged 18 to 24, lived at home with their parents in 1985; most elderly men still lived with their wives, while elderly women were more likely to live alone than with their husbands in 1985. The rapid growth in unmarried couple household during the 1970s has slowed in recent years. Charts, tables, and appendix tables which pertain to the data are included in the document. (APG)