Question

For the first hundred years of the United States, only white males were able to vote. Since then, amendments to the Constitution have made it so that any citizen aged 18 or older can vote. Which amendments granted different groups the right to vote? Why were amendments needed to expand voting rights?

Answer 1

15th amendment- no voter discrimination of race 
19th- women can vote
23rd- gives Washington D.C. the right to vote
then the 26th amendment lowered the voting age to 18.
This was because many things change over time and the U.S. thought of more things to be added to the Constitution