On this day: July 1

Published On: Jun 28 2013 03:06:05 PM CDT   Updated On: Jul 01 2014 01:00:00 AM CDT

The Battle of Gettysburg begins, America's first zoo opens, the first Tour de France starts, the Sony Walkman hits the market, the PG-13 movie rating is introduced, and the Deepwater Horizon oil spill breaks an unfortunate record, all on this day.

OTD July 1 - Non-Proliferation Treaty
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1968: The Treaty on the Non-Proliferation of Nuclear Weapons is signed in Washington, D.C., London and Moscow by 62 countries. The treaty is aimed at preventing the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy and to further the goal of achieving nuclear disarmament and general and complete disarmament. On May 11, 1995, the treaty was extended indefinitely.

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