Aprimary reason for the passage of the 14th amendment in 1868 was to

14th Amendment to the Constitution Was Ratified, July 28, 1868

On July 28, 1868, the 14th Amendment to the United States Constitution was ratified. The amendment grants citizenship to "all persons born or naturalized in the United States" which included former slaves who had just been freed after the Civil War. The amendment had been rejected by most Southern states but was ratified by the required three-fourths of the states. Known as the "Reconstruction Amendment," it forbids any state to deny any person "life, liberty or property, without due process of law" or to "deny to any person within its jurisdiction the equal protection of the laws."

Other groups tried to use the 14th Amendment to further their causes. Women attempted to use it to proclaim their right to vote, and African Americans tried to use it as well. On May 18, 1896, the Supreme Court ruled in the case of Plessy v. Ferguson that "separate but equal" facilities were considered sufficient to satisfy the 14th Amendment. It wasn't until May 17, 1954, however, that the Court reversed the Plessy decision, bringing the era of government-sanctioned segregation to an end.

It was the 15th Amendment, ratified in 1870, which finally gave African Americans the right to vote. It states that "the right of citizens of the United States to vote shall not be denied or abridged by the United States or by any state on account of race, color, or previous condition of servitude." In practice, however, it took almost 100 more years and the passage of the Voting Rights Act of 1965 to remove barriers such as poll taxes, literacy tests, and intimidation that prevented African Americans and other people of color from freely exercising their right to vote. Note that the 15th amendment makes no mention of sex. It was not until the passage of the 19th Amendment in 1920 that women were explicitly given the vote.

it was certainly a debatable decision, mainly because it was based primarily on political - and not on legal or social - views. since the congress at that time was led by members of the republican party, and the territory that the tribes wanted to turn into an exclusively indian state was predominantly democratic, the proposal (as expressed in the constitution) did not succeed, but the constitution itself proved to be of crucial importance in the creation of the state of oklahoma, and, most importantly, it guaranteed the involvement of representatives of the indian tribes in the government of the future joint state.  

as a member of congress, i would have voted to ratify the constitution, or at least to have it tabled. ignoring it was an interested and partial decision.  

that is probably something for you to answer