Trying to trace my grandfather's brother Robert Martin who emigrated to America

[Rustymar1]

My grandfather's brother, Robert Martin, (Son of Robert Martin sr. and Susanna Hart) born 28th March 1880 in the townland of Raleagh, Crossgar, County Down emigrated to America with his childhood sweetheart (name u/k) early in the 20th century and, according to elderly relatives, they opened a small hotel in Philadelphia, Pennsylvania. I would appreciate any advice from some of the more experienced researchers on this site as to how best to go about tracing Robert jr. Thank you.

[Genealiza]

Is this their marriage on www.familysearch?

https://www.familysearch.org/ark:/61903/1:1:249S-XJ8

[Genealiza]

If so, here is the 1910 census:
https://www.familysearch.org/ark:/61903/1:1:MGD5-W9Z
bartender in a saloon

1920 census:
https://www.familysearch.org/ark:/61903/1:1:MXSC-DP7
salesman in grocery store
Letitia is a  boarding house keeper

1930 Census:
https://www.familysearch.org/ark:/61903/1:1:XH4D-9J5
Robert:  from Northern Ireland, manager grocery store
Letitia:  no occup
James Beattie:  bro-in-law:  manager grocery store
Anna S Carney:  sis-in-law:  trained nurse, general practice

1940 Census:
https://www.familysearch.org/ark:/61903/1:1:KQ4S-T3G
Robert is transcribed as "Albert"--manager, grocery store


Pennsylvania Death Certificate

Robert Martin: 
DOD:  24 Dec 1944
DOB:  28 Mar 1882
Residence:  1332 Jerome, Phila., PA
Spouse:  Letitia
Mother:  Susanna Webb
Father:  Robert Martin

[Rustymar1]

Amazing Genealiza and so quick too. Thank you very much.

[Genealiza]

WWI Draft Registration Card:
https://www.familysearch.org/ark:/61903/1:1:K6K9-5QQ

I don't see the WWII DRC on family search, but Anc. has it
Robert Martin
DOB:  28 Mar 1882
POB:  County Down, IRE
Address:  1332 Jerome, Phila., PA
Contact:  Letitia Martin
Employer:  American Stores Co.
Height:  5' 7"
Weight:  16
Complexion:  light
Hair: gray

[Genealiza]

findagrave:  Robert:  https://www.findagrave.com/memorial/169442129/robert-martin

Letitia:  https://www.findagrave.com/memorial/169442134/letitia-martin

[Rustymar1]

At least Letitia had a long life. 

[Genealiza]

I'm not seeing her in the PA death certificates.  She might be the one who died in Cape May, NJ.  Maybe someone else can find the obits for you.

Glad so much information was available for you.

MODIFIED:  his obit appears in The Philadelphia Inquirer, 26 Dec 1944

[Genealiza]

Stillborn child:  https://www.familysearch.org/ark:/61903/1:1:JK9V-VB8

Birth of daughter:  https://www.familysearch.org/ark:/61903/1:1:HHLL-ZTT2