To consider:
A Ben Hiram Rock, born Nov.26,1877, registered for the WWI draft in Bernalillo County in 1918;his nearest relative was given as "Mrs.M.E.Rock" of Canby,Minnesota; he was ill at the time with "lung trouble".
There is a death record for a Ben Hiram Rock,born Nov.26,1877 in IL,died Oct.28,1919 in Canby,Yellow Medicine Co.,MN;parents E.H.Rock and Martha Oakes. In which case, Edwin Rock and family lived in IL,then SD and then Canby,MN.