The three brothers were John, William, and James. I'll have to search, but I know that I have a copy of a family history from a Pennsylvania Appleby reunion in the late 1800's I believe. I don't recall there being any mention of wives or children accompanying the brothers on their immigration voyage though.
I don't have more info on William or James, but John had 6 children, John, Alexander, Magaret, Jane, Nancy, and Martha.
My wife is descended through the latter John, who married Mary (Molly) Moreland in 1810 in Spring Run, Franklin Co., PA. They ahd 8 children: William, John, Alexander, Ann Eliza, Thomas, Mary Jane, Margaret Ellen, and Rosanna.
Of those 8, John (d. 7/14/1856) married Priscilla Montague. They had Daniel Curtlett (b. 1/14/1840), Thomas A. (b. abt. 1844), John Scott (b. 6/20/1847), James McGinnis (b. 5/26/1850; d. 6/25/1907 in Blairsville, Lindiana Co., PA), and George Sharrer (b. 6/17/1853).
James McGinnis Appleby m. Eliza Welch. They had Robert Harold (b. 10/19/1883; d. 8/30/1966 in Harrisburg, PA), Helen McLaughlin, Kenneth Meridith, John Winfred, Winfred, William, George Montague, Charles Edwin, and James Roscoe.
As far as I know, all of the above (except for the first immigrants) were born and most died in PA.