The complete census (all years) is available on Ancestry.com. Only 1920 and 1930 are indexed. What name are you looking for and do you know the township where they resided? It is a tedious job but you can browse through the census images page by page. I have found that often the indexes don't help much because of the many various ways of spelling a name. You need to be accurate especially for given names. Also the 1880 census is available on the Family History Site. They have an every person index with a connection to the household. It is possible to access "previous" and "next" households or individuals. They do not have the page images.