I 100% agree the blade profile suggests N. American influence (Mexico, SW United States, or thereabouts).  
However, am I wrong that the 
buffalo horn hilt , its shape, and proportions is reminiscent of Philippine influence, as shown in the following threads:
thread 1 
thread 2 
thread 3 
thread 4 
and with a lot of similar examples, 
thread 5 
I fully concede that some similar knife themes would have popped up in different regions of Spanish colonial influence.  Again, I feel the horn hilt leans away from a N. American origin, but perhaps an imported blade found its way onto a handle of indigenous material.  I'm OK with either conclusion, but I'll have to claim another bookcase if I now have begun a collection of Mexican edged items.  My wife will be much more pleased if this could stay with my Asian items