Shriners started in 1870. This was after most Grand Lodges had outlawed alcohol. There was a group that met for lunch at the Knickerbocker Cottage on Sixth Avenue in New York. They wanted to have more fun as they felt most lodges because too stodgy.
It was started by Dr. Walter Fleming and a traveling actor named Billy Florience. Florence created a fun little play and Fleming liked it so much they added the concept to their meetings, with help from Charles McClenachan, William Sleigh Paterson and Albert Rawson. In 1872 they little group decalred themselves to be the charter members of the Mecca Temple of the Ancient Arabic Order of the Nobles of the Mystic Shrine (A.A.O.N.M.S. for short, which rearranged spells A MASON), and was shorted to Shriners.
Today there are close to 500,000 members with 191 Shrine centers or Chapters.
That all being said, and may have been more info then you were looking for, all Shriners are Masons, however not all Masons are Shriners. Before the year 2000, you had to become a Freemason, then after becoming Master, go through either the Scottish or York Rite, before you are allowed to join the Shrine. Today, you just have to be a Master Mason. I've known a few people who joined just to go to the Shriners.
That all being said, I think it is a great organization. The charity they support, Shriners Hospitals are amazing. For those that have not heard, there was a plane crash recently here in Fl. There was a young boy who has been burnt very badly. The Shriners flew him to Cincinnati, Ohio burn center from here in Florida. They boy will receive all medical treatments for free there. Not only that, they are paying for the family to be flown up, lodging and meals while the son receives treatment. The family will pay nothing for all of this. They can donate, if they wish, but it is not required. Their hospitals are truly a gift to those in need.