These congregations generally accept the description "non-institutional", although they do not officially identify as such on signs, letterhead, or other official documents; some consider pejorative the epithet "anti" with which they have been called by some in the usually larger mainstream Churches of Christ since the 1950s and 1960s, and likewise the similar term, "non-cooperative". They identify as part of the original church started by Christ. The 19th century Restoration Movement resulted in an increase in the number of U.S. members.