This may be a bit of a long shot, but if James Edward Allan was born in the U.S. in 1891 and was still living there in 1918, it's possible (although not certain) that there's a U.S. WWI draft registration card for him.
All males born between a given date in 1877 and a given date in 1897 were required to register for the WWI draft. It was done pretty much in two passes, one in June 1917 and the second in Sept. 1918. If James was included in the first pass, there's probably a card for him.
The cards include D.O.B., occupation, marital status and a contact person (for married men usually their wives, for single men usually a parent or sibling).
Names may be misspelled and DOBs are often off by a year, but you might be able to find a short list of viable candidates, with the caveat that if he wasn't recorded in the Jun 1917 batch, he may have emigrated before the second pass happened in Sept. 1918.
WWI draft registrations are on FamilySearch.org:
https://familysearch.org/search/collection/1968530?collectionNameFilter=false
and on Ancestry.com:
http://search.ancestry.com/search/db.aspx?dbid=6482