Those two spikes also coincide with 50th and 100th anniversaries, roughly speaking. In many southern communities, the urge to memorialize their dead or gallant soldier sons, brothers and husbands sprang up rather quickly after the war's action petered out, but in other cases they didn't bubble back up to the surface until meaningful anniversaries perhaps reminded them that they never did "enough" at the time to memorialize. But still, it's an interesting graph, and I'm certain there was also a measure of obstinance in holding on to the Lost Cause and its characteristics.