Preston's two-census method of demographic estimation is applied to three pairs of reconstructed censuses from the records of a migrating Mennonite church congregation covering the period 1780-1890, The three pairs of censuses correspond to three periods (1780-1790, 1850-1860, and 1880-1890) and to stays in three settings (Prussia, Russia, and Kansas, respectively). The Mennonites' stay in Prussia was a period of hardship. In Russia they expanded their economic base and developed new farming methods, dramatically increasing their productivity. The Mennonites took these skills to Kansas, where they continued to be successful. The increase in life expectancy at age 5 corroborates this picture. The Prussian period exhibits the shortest life expectancy for both sexes. After the move to Russia, life expectancy increased for both sexes and continued to increase with the move to Kansas. The model also provides limited evidence for fertility depression following the move to Kansas.