Mar 1848–?? 1855California Gold Rush
29 Apr–17 May 1848US debatesannexing Yucatan
19 May 1848Mexico ratifies Treatyof Guadalupe Hidalgo
29 May 1848Wisconsinbecomes US state
14 Aug 1848OregonTerritoryorganized
17 Aug 1848Yucatanrejoins Mexico
Aug 1848–May 1849Los Altos brieflyindependent
Jan 1849Colony ofVancouver I.formed