The United States National Memorial Arch is probably the park's most recognizable symbol. Standing 60 feet high, the arch has stood tall above Valley Forge since it was dedicated in 1917.

When the idea for the arch was proposed in 1910, the plan originally called for two arches: one at each of the two entrances to the park. However, the plan was changed to a single arch, which was constructed at the intersection of Gulph Road and Outer Line Drive.

The arch is modeled after the victory arches of Ancient Rome and is a symbol of victory for the Americans over the British forces. Inscribed at the top of the arch is a quote from George Washington:

"Naked and starving as they are

We cannot enough admire

The incomparable Patience and Fidelity

of the Soldiery"