The NPA was founded on 1 March 1956. It developed from the "Kasernierte Volkspolizei" (Barracked People's Police), which was started in 1952. Serving with the army was voluntary at first. Conscription was introduced on 24 January 1962. Conscription was for male citizens between the ages of 18 and 26. If they were selected, they had to serve in the NPA for 18 months. The NVA was at its largest in 1987. It had about 175,000 soldiers at this time.