Midwestern celebrity roots

Paula Stuart-Warren of Zimmerman (Sherburne County), Minnesota, blogging at Paula's Genealogical Eclectica, is happy to hear that the BBC's "Who Do You Think You Are?" may be coming to NBC.

whenever I see an obituary of some singer or actor that has mention of upper Midwest roots, I do some research to just see where that person fit into the history of the upper Midwest. It has been interesting to see what the ancestral towns are and what the rest of the family was doing in times past.

Past projects she's worked on professionally include the Beach Boys and John Berryman. Hmm, there's no obituary yet, but does anyone have the genealogical scoop on how Dave Letterman's Midwestern roots make him funny? Or long-lasting?