What did president grant pass to prevent southerners from using fear to shut african americans out of the political process?

Under the presidency of Ulysses S. Grant, between 1870 and 1871, the Enforcement Acts were passed.  

These three bills were criminal codes proposed to defend African-Americans’ political rights threatened by the Ku Klux Klan (KKK) and other white supremacy organizations.

They were created to guarantee particularly the right to vote, as well as to hold office and receive equal protection of laws.

they made rome the dominant power in the mediterranean.

a. the astrolabe could determine the correct latitudinal location of the ship