There are two projects called The USGenWeb Census Project. They are at rootsweb.com/~cenfiles and us-census.org
They are managed by different USGenWeb members, their Web site pages were designed by different people and have some differences in the features they offer. They both never have enough volunteers to help transcribe census pages to put online. Please consider visiting their Web sites and offering your help.
It is only those plain text census pages transcriptions and associated notes that you will be searching, not their Web sites. Both projects also offer text files that are indexes to the census pages, with the names of the people in alphabetical order found on the census pages, along with the file name of the census page they are on. Since we index the census pages themselves, we don't index indexes.
Search Us is not meant to be a substitute for visiting the census projects Web sites.
us-census.org has some census indexes online which currently do not have transcriptions of accompanying census pages online. We do not index those indexes, but you can easily find them by visiting their Web site.
Both rootsweb.com/~cenfiles and us-census.org offer their own formats and methods for linking some transcribed indexes and/or census pages, to the actual census images the transcriptions came from, on a limited basis for some areas. You can easily find those pages with links to images by visiting their Web sites.
During your searching, you may at times get results for the same census item from both census projects. That would be because they both have a transcription of that item. At the end of each individual search result is the URL of the page the result was found on. That URL will show you which of the two census projects has the page.
Search Us Census Projects is updated weekly. Both census projects have their own search which may or may not be more recently updated.