Ether 10:12 says that "Morianton built up many cities." According to Warren and Palmer, it appears that during this time period of Morianton, "city" life became commonplace. The people evidently grew in both numbers and prosperity. That suggests significant gains in agricultural productivity, such as was demonstrated in the work by Flanner and Marcus (1983) on the Olmecs. If we can compare the Jaredites somewhat to the Olmecs, then the Jaredites apparently tied together advances in maize production with innovation in irrigation. That greatly reduced their dependence on weather conditions for food and set a pattern that would be followed elsewhere in Mesoamerica.
A very good illustration of a site from that period is San Jose Mogote. The residents developed an efficient irrigation system to improve agricultural productivity and were then able to concentrate also on crafts. [Bruce W. Warren and David A. Palmer, The Jaredite Saga, 7-5, 7-14, unpublished]
Ether 10:12 Morianton built up many cities (Illustration): Figure 7-4 Photo showing Warren and Palmer at San Jose Mogote by the temple [Bruce W. Warren and David A. Palmer, The Jaredite Saga, 7-14, unpublished]