Wikipedia:Selected anniversaries/June 30
June 30: Independence Day in the Democratic Republic of the Congo (1960).
- 1864 - U.S. National Parks: U.S. President Abraham Lincoln granted Yosemite Valley and the Mariposa Grove of Giant Sequoias to California for "public use, resort, and recreation".
- 1894 - London's Tower Bridge, a combined bascule and suspension bridge, opened.
- 1905 - Albert Einstein (pictured) published the article "On the Electrodynamics of Moving Bodies" and introduced the theory of special relativity.
- 1971 - The Soyuz 11 spacecraft depressurised during reentry, killing cosmonauts Vladislav Volkov, Georgiy Dobrovolskiy and Viktor Patsayev.
- 1997 - During an internationally televised ceremony, the United Kingdom officially transferred sovereignty of Hong Kong to the People's Republic of China.