On a parallel thread, I've got stuck looking for an overview of Irish Catholic emigration in the Colonial period.
My present grasp doesn't go much beyond Charles Carroll, as a well-off landowner, emigrating from the County Offaly to Maryland in 1706 — and, of course, George Calvert founded and intended Maryland as a refuge for Catholics. Charles Carroll's grandson of the same name was the one Catholic signatory of the Declaration of Independence.
Emigration from Ulster (i.e. mainly Protestants), after the War of Independence, patriotically went elsewhere. Catholics nobly filled the gap. But what do we know about the earlier times?