A reference that may be useful:
Byram, Sussex County, New Jersey:
In 1819, Gamaliel Bartlett bought the upper forge, grist-mill, and tavern, and conducted all of the enterprises until 1825. In 1823 the Stanhope post-office was established, and Gamaliel Bartlett appointed postmaster, the office being kept at the tavern, which was known as the Stanhope House. Andrew A. Smalley, who was the second post-master, was a clerk in Robert Bell's store, and there the office was then located. In 1823 Bartlett & Rhodes opened the second store, and after them it was kept by Jacob Lowrance and Mr. Van Deeren, but there was no place of trade worthy of much commendation until Robert P. Bell built and opened his store in 1833.
Source: History of Sussex and Warren Counties, NJ. With illustrations and Biographical Sketches of the Prominent Men and Pioneers. James P. Snell. (1881), p. 467.