The KdA made its first public appearance at the annual May Day demonstration on May 1, 1954, and were visible in public during the Hungarian Revolution of 1956 in case of a similar revolt in the GDR. A central school for KdA leaders was set up in Schmerwitz in 1957, and the organization received its official name "Kampfgruppen der Arbeiterklasse" in 1959. The largest use of the KdA occurred during the construction of the Berlin Wall from 13 August 1961, with over 8,000 personnel (about 20% of all military units) mobilized to participate in the effort. The best-trained and most-politically reliable KdA units and members from Saxony, Thuringia, and East Berlin participated in the construction and guarding of the Berlin Wall in the summer and autumn of 1961. During the six-week deployment of the KdA to the East Berlin-West Berlin sector boundary, only eight members defected to the West, indicating a high state of morale and faith in the SED. By 1966 and 1967, the total strength of the KdA was 181,500 "fighters" ("Kämpfer") which was divided between "asset security forces" and "operational reserves". Units whose districts bordered West Berlin and West Germany received better equipment and were directly subordinate to the district management of territorial defense.