C-SPAN offers a number of public services related to the network's public affairs programming. C-SPAN Classroom, a free membership service for teachers, began in July 1987 and offers help using C-SPAN resources for classes or research.[1] The C-SPAN School Bus, introduced in November 1993, traveled around the U.S. educating the public about government and politics using C-SPAN resources, and served as a mobile television studio.