Dear Chris Kelly,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located the Population Schedules for the 1900 Census, and the Population Schedules for the 1910 Census, the Population Schedules for the 1920 Census, the Population Schedules for the 1930 Census, and the Population Schedules for the 1940 Census in the Records of the Bureau of the Census (Record Group 29) that may contain information about your grandfather. Some of these schedules have been digitized in part. The 1940 Census schedules are digitized and available using the Catalog. See NARA’s 1940 Census Records web page for more information. For access to the non-digitized schedules, please contact the National Archives at Washington, DC - Textual Reference (RDT1) via email at firstname.lastname@example.org.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT1. We apologize for this inconvenience and appreciate your understanding and patience.
For information about the U.S. Census, see the Census Bureau technical documentation and questionnaires.
You may wish to search Ancestry.com for the U.S. Census. TThere may be a fee for using Ancestry. Instead, check for access at your local library as many library systems subscribe to these sites, making them free for their patrons.
We also suggest that you review the FamilySearch Research wiki for Massachusetts Directories and search for your grandfather in the Boston City Directories during the years he lived there. Occupations were often noted in directory entries. Plus. we suggest that you search online newspapers from the Boston Public Library for reference to your grandfather as well. In addition, the FamilySearch Research wiki for Suffolk County, Massachusetts Genealogy may be useful.
We hope this is helpful. Best of luck with your family research!