A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: John D. Howard
Date: 2018 Jun 10, 08:17 -0700
You might include info and dates on the US Coast Survey, est. 1807 then re-established in 1832. It was they, not the USNO, that established the longitude of the American cities and made and published accurate charts of the coastline.
The US Coast Survey developed the system of using the telegraph to determine longitude in 1847. It was picked up and used around the world - only superceded when radio was developed. They also published the first US Aeronitacal Charts in 1926.
There was a similar unit in the UK ( Ordiance Survey ) that made maps but I do not know the history very well.