Ken Burns' excellent (and incredibly thorough) documentary on Baseball from 1840's to 2009 is now on YouTube to view in its entirety (unless the copyright lawyers get it taken down)

And absolute must watch for all baseball fans.   

1st Inning:1840 -1900 http://www.youtube.com/watch?v=81J2ezwHicg

2nd Inning: 1900-1910 http://www.youtube.com/watch?v=T65-g6qGxg0

3rd Inning: 1910-1920 http://www.youtube.com/watch?v=9z0E5FOSBrc

4th Inning: 1920-1930 http://www.youtube.com/watch?v=T_PP6g_8P0E

5th Inning: 1930-1940 http://www.youtube.com/watch?v=-R51ZzDt39E

6th Inning: 1940-1950 http://www.youtube.com/watch?v=rhv1KwkgTFE

7th Inning: 1950-1960 http://www.youtube.com/watch?v=yQIfz6_6T9k

8th Inning: 1960-1970 http://www.youtube.com/watch?v=rhl2S_1ARDE

9th Inning: 1970-1993 http://www.youtube.com/watch?v=8tJ0Gxs6Ga8

10th Inning: 1994-1998 http://www.youtube.com/watch?v=wPKMpODlLkI

10th Inning: 1999-2009 http://www.youtube.com/watch?v=SUfJMU7oQZM