He kept the people fed and public works projects staffed using a labor tax.
Manco Capac was the first Sapa Inca who started the tradition of split inheritance. Split inheritance works by keeping the deceased Sapa Inca's possessions entitled to him. The next Sapa Inca will have to obtain his own wealth. This eventually led to the birth of Inca State. The conquered lands gave Inca, Mit'a--a tribute to the state. The tribute kept the laborers fed and public works projects accomplished.