Both shapefiles have over 14,000 rows in their attribute tables, with 150 different types of crops which I have recategorized using Python into 12 categories. I can look at the maps side by side and see changes, but if I want to know what the acreage of a crop in the second map replaced in the first map, it seems there should be a way to do that. I tried "Table Compare" in the Data Comparison toolbox, but it didn't like that the number of rows in the two tables are not exactly the same. Any suggestions?