Measuring America: The Decennial Census from 1790 to 2000 - A Guide to the US Census
Have you ever wondered what something means in the US Census? Why did the Census Taker record things the way they were recorded? Now you can find out! The US Census Office has released a guide to the US Census that provides instructions the Census Takers were told and how they were to record the information they collected.
The US Census Bureau's Jason Gauthier has produced a book that will be extremely useful to those of us trying to figure out the US Census. The book is 148 pages and covers every Census from the first one in 1790 until to the one in 2000. You can read more about the book at the Legal Genealogist Blog.
Or, you could simply download the book for free from the Census Bureau and read it yourself. It comes in searchable PDF format.