Trivial Tuesday, Today Only

I found some interesting facts today while trying to find inspiration for a post, so I decided to ask you some questions today.  By the way, the title has to do with the trivia.

On April 20, 1912, two baseball parks opened in the US.  What were they?

On April 20, 1902, Marie and Pierre Curie refined this compound.  What was it?

On April 20, 1862, this pair completed the first pasteurization tests.  Name them.

On April 20, 1985, the ATF raided the compound of this extremist group.  Who was it?

On April 20, 2008, she became the first woman to win an Indy Car race.  Name her?

There you go, some are easier than others.  Also, did you notice a pattern to the questions?  Have a good evening.