History of Antietam National Cemetery (page 18)
by the United States Burial Corps, detailed by the General Government for the purpose, under the superintendence of Lieutenant JOHN W. SHERER, and they continued their work until January, 1867, when, by reason of the severity of the weather, operations in that department were stopped. There had been removed up to that time about three thousand bodies. They resumed work in April, 1867, and finished their work in August of the same year.