RAW CENSUS DATA FINDS THAT PRISON INMATES, BOTH MALE AND FEMALE, ARE TWICE AS LIKELY TO BE NEVER-MARRIED; THREE TIMES AS LIKELY TO BE DIVORCED, SEPARATED, OR WIDOWED; AND HALF AS LIKELY TO BE MARRIED AND LIVING WITH SPOUSE AS THE GENERAL POPULATION. HOWEVER, PRISON INMATES ARE DISPROPORTIONATELY YOUNG (18-22 YEARS OF AGE), MALE, AND NONWHITE. THIS STUDY SURVEYS THE POPULATION OF INMATES IN ILLINOIS STATE PRISONS AND COMPARES IT WITH THE ILLINOIS GENERAL POPULATION. WHEN CONTROLLED FOR AGE, IT IS FOUND THAT, EXCEPT FOR 18- AND 19-YEAR-OLDS, THE CENSUS FINDINGS ARE VALID--PRISON INMATES ARE CONSISTENTLY LESS LIKELY TO BE MARRIED. HOWEVER, 18-AND 19-YEAR-OLDS ARE FAR MORE LIKELY TO BE MARRIED THAN THE GENERAL POPULATION. THERE WERE ONLY 128 FEMALE INMATES, NOT ENOUGH FOR STATISTICAL ANALYSIS. HOWEVER, THE VAST MAJORITY OF THE FEMALE INMATES HAD BEEN MARRIED. WHEN RACE IS CONSIDERED, BOTH SIMILARITIES AND DIFFERENCES IN MARRIAGE PATTERNS ARE OBSERVED. AMONG BOTH BLACK AND WHITE INMATES THE DIFFERENCES BETWEEN INMATE MARRIAGE PATTERNS AND THE GENERAL POPULATION INCREASE WITH AGE. HOWEVER, BLACK INMATES ARE MORE LIKELY TO BE MARRIED THAN WHITE INMATES AND ARE LESS LIKELY TO BE SEPARATED OR DIVORCED, AND BLACK MARRIAGE PATTERNS AMONG INMATES ARE MORE SIMILAR TO MARRIAGE PATTERNS OF THE BLACK POPULATION AS A WHOLE. THE PROBLEM OF OBTAINING RELIABLE DATA AT INTAKE IS DISCUSSED, AS IS THE EFFECT OF IMPRISONMENT ON A MARRIAGE. IT IS SUGGESTED THAT THE NONMARRIED STATE OFFERS LESS SUPPORT UPON DISCHARGE AND MAKE HALFWAY HOUSES OR COMMUNITY SUPPORT AGENCIES VITAL FOR SUCCESSFUL REENTRY INTO SOCIETY. GRAPHS PRESENT THE FINDINGS. REFERENCES ARE APPENDED. (GLR)