This is where it all starts. The North American Industry Classification System (NAICS) has replaced the U.S. Standard Industrial Classification (SIC) system. This site includes tables to NAICS-to-SIC and SIC-to-NAICS conversion. NAICS is the key to using and understanding economic statistics collected by the U.S. Census Bureau.
Many databases, including Business Source Complete and IBISWorld, use NAICS numbers to classify articles about industries, so knowing the NAICS numbers for industries will help you research industries within databases.
For a comprehensive overview of the NAICS purpose, structure, and classification system, go to the US Census website: https://www.census.gov/programs-surveys/economic-census/guidance/understanding-naics.html
From the website: "The Bureau of Economic Analysis (BEA) produces economic accounts statistics that enable government and business decision-makers, researchers, and the American public to follow and understand the performance of the Nation's economy. To do this, BEA collects source data, conducts research and analysis, develops and implements estimation methodologies, and disseminates statistics to the public."
To find in-depth industry analysis from the BEA, see their page on Industries (https://www.bea.gov/resources/learning-center/what-to-know-industries) for links to historical analysis of GDP by industry, gross output by industry, input-output accounts, and more.
Unlike the Decennial Census, which takes place every ten years and counts the United States population, the Economic Census takes place every five years. The most recent Economic Census took place in 2017, with the next one scheduled for 2022. The Economic Census is a comprehensive survey of business and industry in the United States. It would require a separate workshop of several hours to cover all of its ins and outs. However, if you should have any questions or would like a brief introduction, please contact Olivia Olivares (firstname.lastname@example.org).
Some interesting and useful offerings from the Economic Census:
The US Bureau of Labor Statistics keeps a concise and convenient list of over one hundred industries in the United States with snapshots of information, including workforce statistics, wages, industrial output, and more.