The aim of the study was an attempt to assess the level of changes in the agricultural farm structure of the United States of America within the years 1978-2017 in the he area. The main purpose of the study was to determine the share and dynamics in selected farm area groups in the process of farm area changes. The number of farms in the years 1978-2017 decreased from 2.29 million to 2.04 million (a decrease of 11%), while the area occupied by these farms decreased from 1,353 million acres to 900 million acres (down 33.5%) [USDA 2017]. The article puts forward the hypothesis that due to the long period of observation and regional diversity in agriculture – area changes in farms will confirm significant differences in the rate at which this phenomenon has occurred. The study shows the significant diversification of land resources, dynamics within the number of farms and land utilization within selected states. While the number of farms in the period under consideration increased in 17 states, it decreased in 33 states. The average area of farms in the case of 25 states increased, while it also decreased in 25 cases. The aggregated ratio of farm structure changes was characteristic of states where the most significant changes in farm structure occurred (Alaska, Arizona, Hawaii, New Mexico, North Carolina, Nevada and Massachusetts). Research confirmed relatively variable dynamics of farm area changes within a single country. Because of larger scale farms, in comparison to other countries (especially the EU region), the process of farm evolution seems to be slower and, in several cases, remains almost the same in terms of farm structure as 40 years ago. Farm area changes in the USA have shown significant spatial diversity.