Perhaps you should try some spelling variations:
"american colonization empire" » "americans colonization empire", "american colonization pre", "american colonization exile", "american consolidation empire"
"american colonial empire" » "american colonial empires"
"american colonies empire" » "american colonial empires", "american coloured empire", "american colonialism empire"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("american colonial empire") OR ("american colonization empire"))) OR ("american colonies empire")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"american colonial empire\") OR (\"american colonization empire\"))) or (\"american colonies empire\"))".
• Removing quotes may allow a broader search: (((( american colonial empire ) OR ( american colonization empire ))) or ( american colonies empire )).
• Adding a wildcard symbol may retrieve word variants: (((("american colonial empire") OR ("american colonization empire"))) or ("american colonies empire"))*.