Alison,

Information should be available on joshua Phillips. A good starting
point would be to request his pension (not military) records from
the National Archives. These records usually include a synopsis of
the vet's military career, family info., and if you request a a full
copy of the file, affidavits from people who knew him. His former
address is usually included.

It is explained how to apply for these records at
http://www.spanamwar.com/geneaol2.htm

Patrick McSherry