A portion of the Trail of Tears ran through the county as part of the United States government's removal of the Cherokee in the 1830s.

Until 1863, the Spartans simply visited loved ones in the military and delivered the equivalent of modern-day care packages.

After Union troops entered Rhea in 1863, the Spartans may have engaged in some spying for Confederate forces.

The members of the Spartans were arrested in April 1865 under orders of a Rhea County Unionist and were forced to march to the Tennessee River.

Once in Chattanooga, Union officers realized the women were not a threat and ordered them released and returned to Rhea County.

This was a result of several causes, such as the completion of the Cincinnati-Chattanooga Railroad in Smith's Crossroads, the rapid growth of Chattanooga, the detrimental effects of the American Civil War, and the emigration of its prominent citizens.

The Scopes Trial, which resulted from the teaching of evolution being banned in Tennessee public schools under the Butler Act, took place in Rhea County in 1925.

A statue of Bryan was recently erected on the grounds of the Rhea County Courthouse.

In 1956, the State Supreme Court upheld a "regular and customary practice among certain of the teachers, during the regular school hours and in the classrooms, to read, or have some pupil read from, the Bible; to ask questions of the pupils concerning the content of such passages; to repeat prayers, usually that prayer known as the Lord's Prayer as it appears in the sixth chapter of the Book of Matthew in the King James version of the Bible; to sing hymns and other religious songs; and to inquire of the pupils as to their attendance or non-attendance at Sunday School," where Sunday School attendance remained compulsory in Tennessee at the time, though that law was apparently—to some teachers chagrin—no longer being enforced.

[7] The court there held that precluding teachers from doing so violated the State Constitution, Article 1, § 3: That all men have a natural and indefeasible right to worship Almighty God according to the dictates of their own conscience; that no man can of right be compelled to attend, erect, or support any place of worship, or to maintain any minister against his consent; that no human authority can, in any case whatever, control or interfere with the rights of conscience; and that no preference shall ever be given, by law, to any religious establishment or mode of worship.

The court then held that it exceeded the Equal Protection guarantees of the 14th Amendment of the U.S. Constitution "to have their children taught what they desire ... subject to qualification that teachers and places must be reputable and things taught not immoral or inimical to public welfare,"[8] a reading of that amendment that has since been overruled as to religious teaching in schools by both the Colorado court that provided the quotation, and by the U.S. Supreme Court.

At the time, though, the State Supreme Court reasoned: "complainants, we feel that they have taken a rather narrow and dogmatic view of these constitutional inhibitions.

In their commendable zeal in behalf of liberty of conscience, and of religious worship, they have overlooked the broader concept that religion per se is something which transcends all man-made creeds.

"[9] On June 8, 2004, a federal appeals court upheld a ruling banning further Bible instructions as a violation of the First Amendment principle of "Separation of church and state".

Whites Creek, a tributary of the Tennessee River, forms Rhea's border with Roane County to the north.

At the state level, Rhea County is part of the 31st district of the Tennessee House of Representatives.

On account of the third-party candidacy of Ross Perot, the Republican candidate received less than 50% in the 1992 and in 1996.

Additionally, Oxford Graduate School, an international graduate-level Christian college serving working adults has its campus in Dayton.