Rawlings manufactures the majority of uniforms for teams in Major League Baseball. I do not think that all teams contract Rawlings for uniforms, but I believe that they do have roughly 70% of teams using their uniforms and equipment.
Themselves
The players get new uniforms for each game!
they all use a bat, a baseball, 9 positions, a coach, a field, bases, and uniforms
New York Yankees
They can wear from 0-99, Major League Baseball won't issue uniforms that have triple digit numbers.
None
Themselves
Yes
The players get new uniforms for each game!
Oakland Athletics
They wear majestic uniforms on the field
San Diego Padres
The 1916 Cleveland Indians who had the number on the left sleeve of home uniforms.
The Brewers.
they all use a bat, a baseball, 9 positions, a coach, a field, bases, and uniforms
The New York Yankees were the first.
Seattle Mariners,Houston Astros