Enacted in 1906, the American
Antiquities Act established the protection of "natural and
cultural resources" in the United States, paving the way for
national monuments and parks. President Theodore Roosevelt
proclaimed four national monuments in that same year. The first
of those was Devils Tower in Wyoming. This massive column of
igneous rock attracts hundreds of thousands of visitors per
year.
The first official national park is Yellowstone in Wyoming,
established by President Grant in 1872. The difference between a
national monument and a national park is that parks are set
aside by Congress for their scenic or natural significance,
while monuments can have historic or scientific significance of
any kind and are created via executive order. Buildings and
ruins, for instance, can be monuments, not parks.