So what does Blood Meridian mean, eh? Well for starters, we need to know that a meridian is a vertical line that wraps all the way around the earth and helps people mark their position. In other words, it's a measure of longitude (vertical) as opposed to latitude (horizontal) that marks a specific line in the earth. When you think of America's expansion westward, it's easy to think of the process as one bloody line moving farther and farther west and even down into Mexico. In this case, the line that marks America's movement westward is a blood meridian, bringing gore and chaos to whatever it touches.
One Mexican man thinks his country has its own blood meridian:
Blood, he said. This country is give much blood. This Mexico. This is a thirsty country. The blood of a thousand Christs. Nothing. (8.34)
In the end, he says that all of the blood is "nothing," either because it doesn't matter in the grand scheme of things or because it's a completely inevitable process. This book takes a really pessimistic view of human nature. It suggests that once you give people the chance to explore and settle new lands, they'll go insane with greed and blood will pour wherever they go. The book isn't exactly a child's bedtime story, and the title can help you realize that as soon as you look at the cover.
It's easy to forget that the full title of this book is Blood Meridian or the Evening Redness in the West. The second title echoes what we've said about the first. The redness here symbolizes blood and violence and the fact that this redness comes at the evening reminds us that this book takes place during the later part—or twilight—of the U.S.'s expansion to the western edge of North America.