He seems to have gone back and forward to USA a couple of times. He has two listings on the Ellis Island site (one as Benjamin Fuslong). In both, it is recorded that he has lost his left leg below the knee.
His first arrival was May 22 1910 and second was March 2 1914. In both cases he was going to join Thomas Busby in Wakefield Nebraska. On the earlier record Thomas is described as brother in law and on the later one he is described as a friend. The later record says he was previously in US from 1909 to 1913 (or previously entered in 1909 and 1913), which doesn't quite match with a 1910 arrival.
UK incoming passenger lists on Ancestry has his (presumably final) arrival in Liverpool (coming from New York) on 16 Jan 1918, his address in England is given as 20 Beecham Road Reading, and his occupation is Baker.
There is an earlier arrival from New York to Liverpool for a Benjamin Furlong also a baker on 10 Feb 1910, no age or place of birth given, so not certain if is the same one, but has same occupation.
He doesn't seem to be on either 1911 UK census or 1910 US census.
I can't find any trace of an Army record for him. If he is the right one, who has lost part of a leg, I wouldn't expect he would be considered fit for military service.