All Major League teams will get new batting practice caps this year (according to ESPN), and the Atlanta Braves caps harken back to the early days of the team's tenure in Atlanta. The caps feature the "Screaming Indian," a sometimes controversial logo that came with the team from Milwaukee.
The Braves franchise began using the logo in 1954 while in Milwaukee; using it first as an alternate logo, then adding it as the sleeve patch, changing the sleeve patch from the Indian with the headdress to the new "Screaming Indian." The logo was originally an outline style logo, then changed to a full color logo, then became the outline style logo again in 1972, the year that the logo actually disappeared from the uniform.
The Screaming Indian disappeared altogether from the Braves (in any official capacity) in 1990, when the logo became the word "Braves" with a tomahawk underneath. The Screaming Indian logo was discarded in part due to pressure from Native American groups who opposed the use of Native American imagery on sports uniforms. The reemergence of the logo is already getting panned by ESPN, who gave the new hat an "F" for unmothballing the controversial logo, and Yahoo Sports, for rolling back the recent gains of removing such imagery from sports uniforms.
Below is a chronicle of these logos, collected from SportsLogos.net.
Braves uniform history can be found here for Atlanta, and here for Milwaukee.
1954 Milwaukee Braves alternate logo:
1957 Milwaukee Braves primary logo: