Many regional scientists employ methods designed to "share down" to States or regions national input/output (I/O) data or coefficients. Much of the data supporting the agricultural sectors of the national I/O tables are compiled from State-level estimates. This report uses these actual State commodity output values, aggregated to the 17 agricultural I/O sectors, to "build up" to national I/O commodity output tables published by the U.S. Department of Commerce for 1982. These tables provide the basic foundation of a workable I/O model. The author explains the methodology used to determine State and sectoral distributions of nonmarketed outputs in areas where estimation was unavoidable. The author also highlights special problems and difficulties building these types of accounts.