Short answers, pulled from the story.
Tennessee voters rejected the proposal on the 9th of February 1861 when 54 percent voted against it. The final count reached 69,675 votes against the proposal compared to 57,798 in favor.
Ulysses S. Grant and the United States Navy captured control of these waterways in February 1862. Union gunboats had been scanning Confederate fort-building along the rivers for months before this campaign began.
Sullivan County and Rhea County were exceptions that remained strongly pro-Confederate while most of East Tennessee supported the Union. These areas held out against Union forces until the region was finally captured in 1863.
Tennessee became the first state readmitted to the Union on the 24th of July 1866 by ratifying the Fourteenth Amendment. This action occurred on the 18th of July 1866 when the state legislature approved the amendment.
African Americans made up 25 percent of the population according to the 1860 census data. Despite holding about one-third of council seats in Nashville, they could not dominate politics due to their demographic proportion.