1851 Canada, Quebec, Megantic census
Soon....
See https://www.census.gov/history/www/faqs/genealogy_faqs/when_will_census_records_be_available.html
See https://www.familysearch.org/blog/en/1950-us-census-release-date/
https://1950census.archives.gov
Also https://stevemorse.org
Brown William, age 62, of Chelsea MA, ED 13-42, sheet 1, page 2, line 2
https://1950census.archives.gov/search/?county=Suffolk&name=brown&page=1&size=100&state=MA
https://1950census.archives.gov/search/?county=Suffolk&ed=13-42&page=1&state=MA