The Dead Ball Era is generally considered to have lasted from the turn of the century into the beginning of the roaring '20s. As the name suggests the game used a "dead" or almost soft ball to play its game. The same ball was usually used for the entire game.
Obviously, the state of the ball was a detriment to home runs. Factor in the large, open parks and you can see that home runs were certainly a premium. Teams were left to rely on the hit and run, singles, bunts and stolen bases to win games.
For pitchers, it was the era of the "spit ball" -- completely legal at the time. Many pitchers relied on the spit ball and other trickery to keep batters on their toes. Some of the most skilled pitchers of all time developed in baseball's Deadball Era, however. Cy Young, Christy Mathewson, Walter Johnson and others were skilled at placing the ball anywhere they wanted on a pitch.
Batters used heavy bats, choked up on the handle and didn't attack the pitch aggressively. This style of batting was typified in some of the best of the time -- Ty Cobb, Joe Jackson and Honus Wagner.
The era also brought the American League onto the scene and onto equal footing with the National League. The Federal League appeared for two seasons and left its mark with a number of baseball parks including Wrigley Field.
The World Series also arrived during the Deadball Era. However, the 1919 World Series -- and the Chicago White Sox -- brought this age of baseball innocence to an end and baseball was forced to make changes in the wake of scandal.