Mass.

Mass. is an older abbreviation of Massachusetts, used long before the two letter postal codes. Census takers were allowed to abbreviate state names in the place of birth column, so abbreviated state names are common in the birthplace column of nineteenth century census pages.

It is also the usual form in Civil War unit names, such as 54th Mass. Inf. Do not confuse it with Miss. (Mississippi), which differs by a single letter in a hurried hand.