In the U.S., such a designation requires passage of federal legislation. This usually involves both houses of Congress passing a bill, and the President signing the bill into law.
In 1951, the 3rd National Park in England and the 4th in the UK.
1910
Yosemite became a national park because of it's waterfalls and wildlife.
June 28th 1980
Rejuvenating Gorongosa National Park, Mozambique
Protecting the Chitwan National Park
Sequoia and Kings Canyon National Park, California
Visit the Kruger National Park in South Africa