Original: The New York Knickerbockers were the first baseball team to wear uniforms , taking the field on April 4 , 1849 in pants made of blue wool , white flannel shirts and straw hats .
Simplified: Baseball uniforms were first worn by the New York Knickerbockers Baseball Club in the 1800s . Their uniforms were pants made of blue wool , white flannel shirts and straw hats .