Found a couple of articles about U.S. 410 in the Google Timeline:
Highway Signs Confusing Around Pasco, Says Council (http://news.google.com/newspapers?id=tGMhAAAAIBAJ&sjid=sIYFAAAAIBAJ&dq=us%20highway%20410&pg=724%2C1335907) - July 4, 1965
U.S. Route 12 Is Urged (http://news.google.com/newspapers?id=DmtWAAAAIBAJ&sjid=D-kDAAAAIBAJ&dq=us%20highway%20410&pg=1462%2C1482489) - April 20, 1966
Route 12 Signs Are Up (http://news.google.com/newspapers?id=J9BYAAAAIBAJ&sjid=FukDAAAAIBAJ&dq=us%20highway%20410&pg=7198%2C3890466) - December 29, 1967
Quote from: AARoads on November 11, 2010, 01:08:06 PM
Route 12 Signs Are Up (http://news.google.com/newspapers?id=J9BYAAAAIBAJ&sjid=FukDAAAAIBAJ&dq=us%20highway%20410&pg=7198%2C3890466) - December 29, 1967
Interesting articles, thanks. That last one (above) said US 12 is "a route which eventually will run from the Atlantic to the Pacific". I wonder where they got that info? I don't know how that could've been accomplished, other than truncating US 12 in the Chicago area and rerouting it eastward, eliminating the Michigan segment. Or maybe an implied route through southern Ontario, re-entering the US at Buffalo? Probably just inaccurate reporting...