This review covers some long-term trends of the Illinois Long-term Selection Experiment and offers some perspectives on the impact of long-term selection on productivity of crops (lucerne, oats, rye, barley, winter wheat, spring wheat, soyabeans, groundnuts, sweetcorn, sweet potato, cotton, green peas, sorghum, maize, rice and potato) in the USA. Discussions on the crop productivity, variability of crop productivity and causes of increased productivity, are provided.