William B. Warne and David F. Conover partnered in July 1865 to succeed the business started by Warne's brother, Edward A. Warne, four years prior. The following year, in October 1866, the company moved from 35 S. 3rd St. to the southeast corner of 7th and Chestnut Street in Philadelphia, Pennsylvania.

Mr. Warne retired from the business in January 1873, selling his interest to D.F. Conover & Co.

Conover recognized the market's familiarity with Warne's name and continued to include "Successors to Wm. B. Warne & Co." in advertisements for over a decade.