Civil rights act of 1866 was passed to

 It gave rights to the U.S. citizens.

Explanation:

It declared that ALL people are born in the United States were U.S. citizens and had certain unalienable rights. Without distinction of race or color plus previous condtion of slavery or involuntary service.  As in makin contracts, owning land/personal protperty , to sue in court and to enjoy the full protection of federal law.

the effect of the ming leaders banning ships with more than two masts was that there was no further construction of ships masts, because there was a surplus. ming emperors disallowed foreign exploration