This is a crown top soda bottle from the earlier 20th century.
According to Bottle Makers and Their Marks by Julian Toulouse, the "P" mark on the base is for the Pierce Glass Company of Port Allegany, PA. This plant was in operation since 1917 and was still in business when Mr. Toulouse wrote his book in the early 70s. I would be surprised if it is still in business today - glass bottle manufacturing has largely vanished from the US.