This paper is the first in a series describing the results of the Longitudinal Manpower Study, a national study of four major manpower programs as they operate in large urban areas. Included in the paper are data gained from the responses of 1,236 Job Corps enrollees concerning their reasons for joining the program, their demographic characteristics and handicaps to employment, and their job histories prior to program entry. Data analysis revealed that: (1) The typical Job Corps enrollee is a black male, 16 or 17 years old, (2) Friends and relatives play a strong role in the youth's decision to join the Job Corps, (3) Enrollees join the Job Corps in hopes of getting a better job, (4) The enrollees' families are somewhat larger with both parents more likely to be present, (5) Few enrollees report physical handicaps but many appear to be subject to other conditions which may restrict their choice of jobs, such as incomplete education and arrest record, and (6) Many enrollees experience a difficult time finding satisfactory work prior to entering the program. (SB)