The idea of a coalition originated in 1999 as a grassroots group of Hispanic citizens who wanted to be involved and organized to gain political clout in an election year. They initially met at the Mexican Mutualista Society building, known as "La Loma", and set as a goal to work for the welfare of the community, together and without territorialism. Later in 1999, the group organized into a coalition called P.A.C. (Political Action Coalition), and began to hold meetings at the Pontiac Public Library, hosted by the former Latin Affairs Office.
The first Hispanic Health Fair was held in May 1999 at Mercy Place. Maria Moyet-Delgado served as chair at that time, but later resigned for personal reasons. Ernesto Mariona was elected to finish the term and preside over the next. Maria Moyet-Delgado returned to preside as chair, and later, Debra Ehrmann would become the actual coalition chair. During the fiscal year 2000 members agreed by vote to collectively call themselves the Oakland Coalition of Hispanic Services Agencies, OCOHSA.
Today, OCOHSA comprises a network of over 35 registered agencies and individuals throughout Oakland County, and hundreds of contacts across the state.