Germany's invasion on poland started it. Hope this helps!
        
                    
             
        
        
        
Answer:
Methodist and Presbyterian missionaries established settlements
Lewis and Clark explored and mapped the interior.
John Jacob Astor made one of the first settlements.
Explanation:
The Oregon Territory was initially an extension of land owned by America until February 14th, 1859 when it was officially recognised as the State of Oregon and part of the Union. 
Therefore, the three events that the United States used as a claim to the Oregon Territory are
Methodist and Presbyterian missionaries established settlements
Lewis and Clark explored and mapped the interior.
John Jacob Astor made one of the first settlements.
 
        
                    
             
        
        
        
Answer:
arguing that Mexicans had "shed the blood of our fellow-citizens on our own soil
Explanation:
 
        
             
        
        
        
Answer:
the 3rd one
Explanation:
The massacre was depicted inaccurately in an engraving by Paul Revere meant to persuade colonists to join the cause for independence.
 
        
                    
             
        
        
        
Answer:Both movements launched nationalist wars that extended over several years.