I recently created some web sites about this Manx man and his wives. He was originally a sailor, then came to the USA as a Mormon pioneer, and ended up in the Mormon Colonies in Mexico.

McNeil Family Timeline is found at: http://www.geocities.com/iflk/mcneiltime.html

"John Corlett McNeil History: A Mormon Pioneer from the Isle of Man to St. Louis to Utah to Arizona to Mexico, including journal entries, family members and pictures of John McNeil, his wives and children" is found at http://www.geocities.com/iflk/johnmcneilhistory.html

An account of Mary Jane Quinn McNeil, 2nd wife of John McNeil (and your grandfather's grandmother), is here: http://www.geocities.com/iflk/maryjanequinnmcneil.html

An account of John McNEIL and Mary Jane QUINN McNEIL: Pioneers Alone, by Wagon, Across the Plains, is here: http://www.geocities.com/iflk/johnmjqmcneil.html

An account of Mary Ann Smith McNeil, 3rd wife of John McNeil, is here: http://www.geocities.com/iflk/maryannsmithmcneil.html

The diary of Mary Ann Smith McNeil, John McNeil's third wife, is here: http://www.geocities.com/iflk/masmcneildiary.html

Enjoy! (This is from my wife's family)