TRIO began with Upward Bound, emerging out of the Economic Opportunity Act of 1964 in response to the Lyndon Johnson's administration's War on Poverty.
"The history of TRIO is progressive. It began with Upward Bound, which emerged out of the Economic Opportunity Act of 1964 in response to the Lyndon Johnson's administration's War on Poverty. In 1965, Talent Search, the second outreach program, was created as part of the Higher Education Act. In 1968, Student Support Services, which was originally known as Special Services for Disadvantaged Students, was authorized by the Higher Education Amendments and became the third in a series of educational opportunity programs. By the late 1960's, the term "TRIO" was coined to describe these federal programs." (http://www2.ed.gov/about/offices/list/ope/trio/triohistory.html)
Additional programs such as the Educational Opportunity Centers (1972), the Ron McNair Post Baccalaureate Achievement Program (1986) and the Upward Bound Math and Science (1990) were created to address the academic and vocational needs of students from low-income and first generation backgrounds, students with disabilities, and veterans.
TRIO Programs are outcome focussed and tend to rely on data to provide mandated interventions to assist student progress from one educational level to the next.