Alan,

I believe Card # 5 in his Lenoir's Independent Company file, which contains this terse information, makes reference to possible service abroad:

Boykin, James

Vol. ADC to Gen. Cantey

Capt. Co. Cav. Ala.

Agenh[sp?]*, C. S. to go abroad

* Agent?

......

Also, on Card No. 4, it shows he surrendered at Citronell May 4, 1865 as a Captain and Staff Officer. Later paroled at Mobile June 13.

No indication as to whose staff he was serving. Cantey’s brigade was then serving in North Carolina, Cantey’s presence unknown as he was ill much of the time late in the war.

...

The last major Confederate army east of the
Mississippi ended its fight beneath an oak
tree at Citronelle, Alabama on May 4, 1865.

Realizing that all hope was lost, Confederate
Lieutenant General Richard Taylor came to
agreement with Union Major General E.R.S.
Canby. The surrender at Citronelle ended
significant combat east of the Mississippi
River.
http://www.exploresouthernhistory.com/citronelle.html