MacIain Chiefs 2005 is the third edition of a genealogy work which was first published in 1990. It was derived from the original work of Cornelius MacKean of Ohio, USA, in 1902, and many MacKean/MacKeen/McCain family researchers, starting in the mid 1980s.

The book traces the descendants of William MacKean, born about 1607 in Argyllshire, Scotland, through Ireland and thence to North America, establishing branches of the family in New Hampshire, Pennsylvania, and Nova Scotia, Canada, and subsequently throughout the continent.

Family oral history relates that William MacKean was a descendant of Clan MacIain of Ardnamurchan, Scotland, and this clan was descended from Clan Donald. The origins of Clan MacIain and the succession of clan Chieftans is described in some detail.

The book contains over 19,000 individual names in 500+ pages, the following is a summary of the table of contents.