When was the fifteenth amendment ratified?

In ohio in 1872, the cleveland massacre was a violent labor dispute at standard oil refineries in cleveland. a takeover by standard oil of the refineries in cleveland. an attempt to stop standard oil from becoming a monopoly. a failed attempt by standard oil to take over other refineries.

Plz ive been stuck on this question forever. in 1753 george washington was sent on a mission to a. build a fort at the point where the allegheny and monongahela rivers form the ohio river. b. attack the french at fort duquesne. c. attack the french at fort neccessity. d. deliver a message to the french demanding that they leave the ohio river.

During world war ii, which battle was the first significant us victory in the pacific?