Today marks the 150 year anniversary of Abraham Lincoln’s Gettysburg Address. Here are five facts about one of history’s most famous — and famously brief — speeches:

1. The Gettysburg Address was not written on the back of an envelope. Despite the popular legend that Lincoln wrote the speech on the train while traveling to Pennsylvania, he probably wrote about half of it before leaving the White House on November 18.

2. Much of the language and thematic content of the speech had been used by Lincoln before. The radical aspect of the speech was Lincoln’s assertion that the Declaration of Independence — and not the Constitution — was the true expression of the founding fathers’ intentions for their new nation.

3. There are five different versions of the speech. The most widely quoted one is the oldest.

4. Now regarded as one of the great speeches of history, the address was initially greeted with criticism by many newspapers. The Democratic Chicago Times called the address “a perversion of history so flagrant that the extended charity cannot regard it as otherwise than willful.”

5. “God” is the only proper name mentioned in the speech. The name of the battle is not mentioned.