What was the trend that the 13th, 14th, and 15th amendment had on the united states?

*The 13th amendment abolished slavery in the United States and provides that "Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States

*The 14th amendment granted 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 15th Amendment to the Constitution granted African American men the right to vote by declaring 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."
 
(By the way, I thought that I should bring to your attention the incorrect use of word choice in your question. A trend is meant to be something that is in style, or generally up to date. You should have used the word "impact" instead)

Sector is best defined as (part).