Why did rome went from having a king to having democracy

"It all began when the Romans overthrew their Etruscan conquerors in 509 B.C.E. Centered north of Rome, the Etruscans had ruled over the Romans for hundreds of years. Once free, the Romans established a republic, a government in which citizens elected representatives to rule on their behalf." - ushistory.org

when the united states took over

facts: the 14th amendment

the 14th amendment addresses citizenship rights and equal protection of the laws.

the 14th amendment was intended to protect the rights of former slaves after the american civil war.

the 14th amendment was approved by congress in june of 1866 and ratified by the states on july 9, 1868.

the 14th amendment establishes that all persons born in the united states are citizens and are guaranteed all the rights of citizenship.

the 14th amendment establishes that the law protects all citizens equally.

in this case the passage of the 14th amendment   that was violated was the last part in which it states that there is equal protection of the law.