A concept that lasted from the late 1870s into the 1980s in
American politics, where the
Democratic Party held a virtual
stranglehold on elected office in
the South. The South was thus considered "solidly" behind the Democrats.
The origins of this came out of the ashes of Reconstruction. White Southerners traced all of their suffering back to the election of Abraham Lincoln, the first Republican President, before the Civil War. The Radical Republicans' insistence on a punitive Reconstruction, while not heeded by President Andrew Johnson (leading to his impeachment trial), compounded the hatred most Southerners felt toward this party. When Reconstruction was finally lifted over the entire South in the Compromise of 1877 and "free" (meaning mostly white) elections were held for the first time since the Civil War, the Democrats were virtually handed the reins.
The Democratic philosophy of the time suited the South anyway. The Democratic party had virtually always been the more conservative of whatever two main parties existed, and the South was (and remains) a conservative region of the country. Despite the growth of a Northern liberal wing of the party, the South remained a lock to send its bloc of conservative Democratic Senators and Congressmen, and to vote for whichever Presidential nominee had a (D) beside his name, up into the 1950s.
It is undeniable that the civil rights movement was the main impetus behind the breakup of the solid South. As Southern blacks were registered to vote, they flocked to the Democratic Party both because the liberal wing of the party supported their movement and because being a Democrat was the only tenable Southern political affiliation at the time (see the end of my primary WU for why). Meanwhile, mostly-white conservatives saw the writing on the wall regarding the liberalization of even Southern state Democratic Parties, and started defecting en masse. Some of the hardcore race-baiters actually chose to be independent, but the main beneficiary of the Democratic exodus was the Republican Party. The Republicans started picking up first state legislature seats, then House seats, then governorships and Senate seats. This swing started to show in the 1970s and 1980s, and was plainly evident by the 1990s.
One side effect of this was the near-disappearance of the old-style Southern Democrat. The closest we have left is Sen. Zell Miller (D-Georgia); Rep. Virgil Goode (I-VA) was one before his 1999 departure and assumption of Independent status.
The Solid South is no more, but its breakdown provided the foundation for what some today call the conservative revolution.