The area was served by a post office called Musquaka,[2] which operated from 1874 to 1895.

[3][4] The Musquaka post office was changed to Ambrose in 1895.

[6] Ambrose's post office was discontinued in 1902;[4] after that, mail was routed through the nearby town of Keswick.

[7] In the early 20th century, the towns of Keswick, Armah, and Ambrose shared a telephone company.

This was known as the Keswick, Ambrose, and Armah Mutual Telephone Company.