Individual Details

Possibly James:

1880 Census. San Rafael, Marin, CA, Hh 25
O. C. Hawkins, 44, constable, b. RI
Mary E., 45, wife, b. NY
Fannie, 10, dau. Oliver C., 8, son. Irene V., 4, dau. - all born CA
Eleanor Shephard, 26, stepdau. All born CA, father b. NC
Abraham Shephard, 24, stepson, express agent.
James G. Shephard, 22, stepson, druggist
Crittenden McC. Shephard, 20 stepson, telegraph operator
Mary F. Shephard, 19, step dau

This doesn't explain why or how he would marry in Carson City, nor how he met Emma Crawford. He is said to have died in San Rafael and be buried Mount Tamalpais Cemetery, San Rafael

I did find this FindAGrave, Memorial #126929548. His son on the same monument.
Marin Journal
December 6, 1888
James G. Sheppard died at his residence, in San Rafael, on Thanksgiving Day, the 29th instant. He had been confined but 3 days, and the sad news of his death was made more shocking by its suddenness. The place of the deceased in our community was unique, in that he had grown to manhood here, had been a boy among our boys, and after a short absence had returned and established himself, not only in a good business, but as a prominent citizen, so much respected, and so thoroughly identified with general affairs that every good cause will miss him.
He took his first step in the profession in L.H. Thompson's store, in San Rafael. Then he spent a couple of years in Tomales, in Dr. Dutton's drug store and laboratory. He was for a time on a naval ship at Mare Island, from which he went to Carson, NV, where he married. Returning to San Rafael some 7 years ago, he bought out Mr. Thompson, and as since conducted the business with great success. As a druggist he enjoyed the fullest confidence of our physicians and all the community, and as a gentleman and citizen no young man in the place stood higher. He had a rugged independence of character, and expressed positive opinions on all questions of public interest, and yet enjoyed the friendship of everyone. He was intensely devoted to his business, yet took a keen interest in public affairs, on all of which he was in accord with the most advanced and an enlightened policy. He was a good businessman, and a good citizen, and had gained so warm a place in the hearts of our people, that his death is mourned as a public calamity. He leaves a widow and one child.

Birth	1858	New York
Marriage	2 Apr 1885	Carson City, Carson County, Nevada - Emma Elizabeth Crawford
Death	29 Nov 1888	San Rafael, Marin County, California

Spouse	Emma Elizabeth Crawford (1860 - 1945)
Child	James Glasgow Sheppard Jr. (1888 - 1933)