WAC programs vary considerably across institutions (McLeod and Maimon 2000). Their theoretical origin has been traced to the work of James Britton and his colleagues at the University of London in the 1960s and to Charles Bazerman's studies of writing in the disciplines in the 1980s and 1990s. WAC is often referred to as a pedagogical reform movement, and faculty members who become involved with writing across the curriculum often find that it has a significant impact on their teaching more generally.

As an institutional program, Writing Across the Curriculum came of age with the publication of Writing in the Arts and Sciences (Maimon, et al. 1981) and with the work of Toby Fulwiler and Art Young at Michigan Technological University and of Anne Herrington at the University of Massachusetts. All of these scholars featured professors in their work from different departments describing both their pedagogy and the kinds of discourse valued in their disciplines. The integration into curricula of both "writing-to-learn" (expressive writing) and "learning to write" (transactional writing) experiences has become a hallmark of WAC programs (McLeod and Maimon).

By 1985, C.W. Griffin's survey of 404 institutions identified 139 WAC programs. That number has continued to grow, with numerous Writing (and Communication) Across the Curriculum programs existing in U.S. colleges and universities today.

According to McLeod and Maimon, (2000) a fully-developed WAC program includes:
(1) faculty development ,
(2) curricular components from the freshman year onward,
(3) student support in the form of writing or learning centers,
(4) assessment of the program and of student writing,
(5) an administrative structure and budget.