Which president started the bull moose party?

The Bull Moose Party was started by President Theodore Roosevelt.

Explanation:

The Progressive Party was an American political party founded in 1912 after disagreements had occurred within the Republican Party. Former President Theodore Roosevelt could no longer agree with the policy of the then president, William Howard Taft. The newly founded Progressive Party chose Roosevelt in 1912 as its presidential candidate. Roosevelt could not achieve the election (Woodrow Wilson Democrat won), but still finished second, ahead of Taft. In 1914, the Progressive Party only achieved a few election profits. The party was abolished in 1916 and two years later the elected members rejoined the Republicans.  

The party is also known as the Bull Moose Party after former President Roosevelt was shot at a campaign in Wisconsin and he reassured the public: "I'm fit as a bull moose." Roosevelt finished his one and a half hour speech despite the injuries.