White entertainers often performed in "blackface" instead of allowing African-Americans on stage. Women were not accepted in most professions. Neither group was allowed to step into a voting booth.
It wasn't until 1869, when the Fifthteenth Amendment was ratified, that males of all races got the vote.
It took another 50 years, with the ratification of the Nineteenth Amendment, for women to finally get suffrage.
The Twenty-Third Amendment gave limited voting rights to the residents of Washington D.C.
Then the 24th Amendment banned poll taxes that some states used to chase ethnic and poor people away from the ballot box. In some places, people needed to own property to vote - not anymore.
During the bitter years of the Vietnam War, Americans realized if young people can be ordered to fight and die, they deserve to choose their leaders. The Twenty-Sixth Amendment lowered the voting age to 18 years.