This guide does not provide detailed information on doing historical industry research but we wanted to touch on it briefly.
Much of the oldest information on various industries is not necessarily found in full-text electronic sources. Instead, access to many articles found in trade magazines is through print or online indices that cover newspapers, periodicals, and journals but which may or may not be business specific. Some trade magazines did also index themselves. The most obvious are Business Periodicals Index, its precursor, Industrial Arts Index, as well as PAIS, Poole's and Reader's Guide to Periodical Literature. Other sources which are not business specific but which can be helpful, include databases containing long runs of newspapers as well as the database American Periodical Series, which contains early journals and magazines.
Also, many of the sources found online that are used for current industry information, have in the past, been published in print and are often available in quite long runs. Publications of the U.S. Census Bureau are prime examples. Economic Census data is published on the U.S. Census Bureau web page going back as far as 1992, but prior to that the Census Bureau published this information in print format in much the same form as it is currently published. In addition, prior to the start of the Economic Census, which began in the 1930's, some business and related economic data was contained in the general Decennial Census. If you want to look for older Census information see Catalog of United States Census Publications, 1790-1945, prepared by Henry J. Dubester, Chief.
Historical Statistics of the United States, Colonial Times to 1970 is available as a 2 volume set and as a freely available electronic resource (resource linked below) for much of the relevant data. In addition, Cambridge University Press has also produced a 5 volume updated millennial edition (also linked below) incorporating data through the 2000 Census, also available for purchase in online form from the publisher.