The official text celebrating Hispanic heritage defines whom it celebrates: citizens, service members, police and border agents. The boundary is written down.
The Latino congressman who proposed Hispanic Heritage Month watched his bill die in committee. The text that became law was introduced by a senator from Illinois.
Hispanic Heritage Month depends on an annual presidential signature. Read as a series, those signatures reveal a shift in timing and another in content.
National Hispanic Heritage Month exists because a president proclaims it annually. What it honors has been here four and a half centuries.