This paper documents the construction of consistent social accounts that cover the period from 1978 to 2001 for the U.S. economy at a two-digit level of aggregation. There are four primary data sources for the construction of the accounts. First, the Bureau of Economic Analysis (BEA) publishes a Gross Domestic Product by Industry (GDPI) series that includes value added by factor and sector (at approximately the two-digit level). The series also includes other useful measures of total intermediate inputs and various double-deflation indices for conversion of current dollar measures into real measures. The second primary data source is the benchmark input-output (BIO) accounts published by the BEA. The input-output accounts allow us to decompose intermediate inputs by two-digit commodity, although they are only available for select years. The third source is the U.S. Department of Commerce (DOC) customs level data on annual merchandise trade (Trade Policy Information Service of the DOC). The final data source is the National Income and Product Accounts (NIPA) also published by the BEA. Given the primary mission of analyzing trade policy, the highest weight is given to maintaining the integrity of the merchandise trade data in the final dataset. We also maintain real two-digit value added by factor and sector. The input-output accounts are used to generate targets for intermediate-input shares. When a year lies between two different input-output observations a weighted average is used to generate the target. To the extent possible, respect is given to the NIPA account in maintaining final demand, income, and balance-of-payments levels. In this document we outline the process used to reconcile each of the data sources. The resulting annual balanced social accounting matrix is suitable for structural empirical work at the two-digit level.