The congress whenever two thirds of both houses shall deem it necessary, shall propose amendments to this constitution, or, on the application of the legislatures of two thirds of the several states shall call a convection for proposing amendments, which in either case, shall be valid to all intents and purposes, as a part of this constitution, when ratified by the legislatures of three fourths of several states, or by conventions in three fourths thereof, as the one or the other mode of ratification may be proposed by the congress; provided that no amendment which may be made prior to the year one thousand eight hundred and eight shall in any manner affect the first snd fourth clauses in the ninth section of the first article; and that no state without its consent, shall be deprived of its equal suffrage in the senate. Which Article if the U. S. Constitution is the passage above from Article IV
Article V
Article VI
Article VII

Article V

Explanation:

The Founding Fathers recognized that as times change, there may be a need to amend the Constitution. They did not however want to make this such an easy task that it would be done haphazardly.

For this reason they laid out the ways the Constitution could be amended in Article V of the Constitution, part of which is shown above, and since then there have been 27 amendments with the Bill of Rights being the first ones.

regarding the law, the 15th amendment was specifically designed thinking in the rights of black free men.

even though ratified on february 3, 1870, the promise of the 15th amendment would not be fully applied for a long time.poll taxes and literacy tests would allow southern states disenfranchise african americans. only in 1965 the voting rights for african americans would be actually able to vote in the south.

in 1965, president johnson signed the voting rights act, which aimed to overcome legal barriers that prevented african americans from voting as it was guaranteed by the 15th amendment to the u.s. constitution.

during the 20th century, the role of the vice president has evolved into more of an executive branch position. now, the vice president is usually seen as an integral part of a president's administration and presides over the senate only on ceremonial occasions or when a tie-breaking vote may be needed.