What is the troubled Caribbean island nation where a president's murder led Wilson to send in the marines and assume American control of the police and finances?

Mexico's president was assassinated in 1913. Almost two years later the U.S., under President Wilson, assumed control of the Caribbean island. Check out this site for the information about this invasion on July 29, 1915.

http://millercenter.virginia.edu/academic/americanpresident/keyevents/wilson?PHPSESSID=44d91630009ddd5e009b3abdd05a5515

ok, so are you saying that this Caribbean island nation is Mexico?
I am confused ><

Wilson ordered the invasion of Haiti. Look at the July 29, l915 date in the site above.

Apologies for any confusion caused. The troubled Caribbean island nation where President Wilson sent in the Marines and assumed American control of the police and finances is Haiti, not Mexico. In 1915, President Wilson ordered the invasion of Haiti due to political and economic instability on the island. You can find more information about this event on the provided website link, specifically looking at the date July 29, 1915.