Which supreme court case found the use of grandfather clauses unconstitutional?

The Supreme Court case that found the use of the grandfather clause unconstitutional is the Guinn v. United States, 238 U.S. 347 (1915). In its decision, the Supreme Court ruled that  the grandfather clause exemptions to literacy tests were unconstitutional. It declared the grandfather clauses as repugnant to the Fifteenth Amendment and therefore null and void.

Towns and small farms are usually for land, lakes, rivers, and seas.they also produce other food, like crops.it's also where animals are, where we get our meat.large plantations normally have forests, where crops are grown for sale. (similar to farms)plantations have larger fields of crops.our wine, sugar canes, and fruits come from plantations.