I am trying to prove John Waldemar or Waldemarson was on the John J Boyd as a passenger on the John J Boyd which left Liverpool England on 12 Dec 1855.
Also searching for a arrival date to USA in New York, am trying to prove info from a letter I have.
For proof you'll want to find the passenger list at the port of arrival.
US National Archives has microfilm of New York ship arrival records - 26 Oct 1855-15 Dec 1855 0175514 17 Dec 1855-31 Jan 1856 0175515 1 Feb 1856- 31 Mar 1856 0175516 1 Apr 1856- 14 May 1856 0175517 the same records are probably also available at an LDS Family History Center - but their numbering system of the microfilm reels will be different.
The information about the ship John J. Boyd indicates that the 12 Dec 1855 voyage from Liverpool to New York was completed on or about 18 Feb 1856. The passengers indicated were Latter-Day Saints of Norwegian, English and Italian origins. The LDS have a CD (or set of CDs) specifically about Mormon emigrants. They might have recorded more identifying information for John Waldemar or Waldemarson that would help find him in earlier Norwegian locations and records. Identification such as when born, where born, etc.
I did find the ship manifest for the John Boyd, left 12 Dec 1855 from Liverpool and arrived in New York 18 Feb 1856 - I did noot find a John (Johan) Waldemar or Waldemarson on the ship manifest.
Some items from the biography match with an article I found about the ship, such as a measle outbereak - also the length of travel in the Biography of about 12 weeks also matches