April 30

1803  The treaty providing for the sale of Louisiana, including most of what would become Wyoming, was signed.

1812    Louisiana became the 18th state, albeit one with an obviously much decreased territorial expanse compared to the territory it represented when sold to the United States.

1869  Union Pacific reached Promontory Point, Utah.

1906  A and B Mines opened at Superior.

1926  The cornerstone was laid for the University of Wyoming's engineering building.  Attribution:  On This Day.  The photo above depicts the building some time in the 1950s.  The one below, in 1986.