Happy Saturday! Here are five notable things that happened this weekend (July 25 and 26), from the establishment of the Post Office to the birth of Louise Brown.

1. 1775 - (Soon-to-Be U.S.) Post Office Established

During the first Continental Congress in 1774, a frustrated newspaper printer made the case for a new, reliable postal system within the Thirteen Colonies. It wasn't until the Second Continental Congress that anyone acted on the idea, naming Benjamin Franklin postmaster general on July 26, 1775.

Franklin was a solid choice as he was the postmaster of Philadelphia, and had served as joint postmaster general for the colonies from 1753 to 1774 (he was fired in '74 for some naughty-but-politically-expedient behavior related to Massachusetts Royal Governor Thomas Hutchinson’s mail).

Franklin only served in his new post for a year, handing it to his son-in-law in November of 1776. But during his brief tenure, Franklin established reliable overnight service between Philadelphia and New York, created a standard rate table based on weight and distance, and surveyed routes stretching from Maine to Florida. He also happened to be in office when the colonies declared independence, making Franklin the first Postmaster General of the United States.

2. 1946 - First Nuclear Bomb Test at Bikini Atoll

The United States conducted the first underwater nuclear bomb test on July 25, 1946. Called "Operation Crossroads," the bomb blew at sea near Bikini atoll. Various obsolete U.S. battleships (plus remnants of the Japanese Navy) were placed nearby to test what happened to them as a "boiling, foaming wall of paper" overtook them, and the whole thing was filmed.

The experiments continued for nearly a decade, with disastrous results for the former residents of the islands, who were evacuated and left without a homeland.

3. 1956 - The SS Andrea Doria Sinks

The Italian luxury liner Andrea Doria collided with the Stockholm in heavy fog on the night of July 25, 1956. The huge Andrea Doria listed to starboard, causing many of her lifeboats to become unreachable.

Fortunately the ship remained afloat for more than 11 hours, long enough to receive aid from the Stockholm and many other ships in the area, most notably the Ile de France. It is the largest civilian rescue at sea in history, with more than 1,600 passengers and crew rescued, and casualties over 40.

4. 1965 - Dylan Goes Electric

On July 25, 1965, Bob Dylan performed a simple three-song set at the Newport Folk Festival. What differentiated this set from his earlier performances at the festival was the band backing him—and that everybody was playing electric guitars through a crappy sound system. This wasn't folk anymore.

When Dylan "went electric" with the tune "Maggie's Farm," he alienated his folk fans and entered uncharted territory. Although he did proceed to play some acoustic numbers, Dylan didn't perform at Newport for 37 years after that day. (For comparison, watch his acoustic magic at Newport the year prior.)

5. 1978 - First "Test Tube Baby" Born

Today, in vitro fertilization (IVF) is a relatively common medical procedure. In 1978 it was headline news, when Louise Brown was born in the United Kingdom. Technically speaking, Brown was conceived in a petri dish (not a test tube), and thirty years later, gave birth to her own first child. Happy birthday, Louise!