July 30 1863:

The Shoshone chief Pocatello signs the Treaty of Box Elder,
bringing peace to the emigrant trails of southern Idaho and northern Utah.

Pocatello was a Bannock Shoshone, one of the two major Shoshone tribes that dominated modern-day southern Idaho.
Once a large and very powerful people, the Shoshone lost thousands to a smallpox epidemic in 1781.
The fierce Blackfoot Indians took further advantage of the badly weakened Shoshone to push them off the plains and into the mountains.
The first representatives of a people who would soon prove even more dangerous than the Blackfoot arrived in August 1805:
The expedition of Meriwether Lewis and William Clark.

On July 30:

1945 - The USS Indianapolis, which had just delivered key components of the Hiroshima atomic bomb to the Pacific island of Tinian, was torpedoed by a Japanese submarine. Only 316 out of 1,196 men survived the sinking and shark-infested waters.

The USS Indianapolis was a heavy cruiser commissioned in 1932, active throughout World War II and sunk in July 1945 (just two months before the end of the war), after delivering a uranium-235 slug and other components for the atomic bomb that was used against Hiroshima. This ship was also the subject of a monologue delivered by Quint in the film Jaws, due to the deaths of a large number of crewmen at sea to shark attacks before the survivors were rescued.

On Aug 1:

1944 - Thirteen-year-old Anne Frank made the last entry in her diary; days later she and her family were taken to the Bergen-Belsen concentration camp, where she died at age 15.

August 1 1910:

The state of New York issued its first license plates on this day in 1910.
Massachusetts, the first state in the nation to issue plates, had been doing so since 1893,
when it introduced iron plates with the registration number etched on top.
The current New York plate, which features the Statue of Liberty, has been in use since 1986.

August 2 1876:

"Wild Bill" Hickok, one of the greatest gunfighters of the American West, is murdered in Deadwood, South Dakota.