"EMIGRATION. . . . Elder John Moon, and others who sailed from Liverpool on the 6th of June, arrived in New York on the 20th of July, in tolerable health and good spirits, as we learn by Brother Moon's letter of the 22nd of July . . . ."
MS, 1:5 (Sep.1840), p. 136
"FIRST COMPANY. -- Britannia, 41 souls. The following is recorded in the history of Joseph Smith:
'Saturday, June 6th, 1840, Elder John Moon and a company of forty Saints, to wit: John Moon, Hugh Moon, their mother, and seven others of her family, Henry Moon, (uncle of John Moon), Henry Moon, Francis Moon, William Sutton, William Sitgraves, Richard Eaves, Thomas Moss, Henry Moore, Nancy Ashworth, Richard Ainscough, and families, sailed in the ship Britannia from Liverpool for New York, being the first Saints who have sailed from England for Zion.'
The Britannia arrived in New York on Monday, July 20th, 1840, from whence the emigrants continued the journey to Nauvoo, Illinois."
Cont. 12:12 (Oct. 1891), pp.441-42
"Sat. 6. [June, 1840] -- Forty-one Saints sailed from Liverpool, England, on the ship Britannia, for the United States, being the first Saints that gathered from a foreign land. John Moon was leader of the company."
CC, p.18
(source abbreviations)