What "department" of the government of animal farm did the pigeons work for?

The military ... ww2 they used them to send messages around the battlefield and trenches :)

A leader of the Whig party and five times an unsuccessful presidential candidate, Henry Clay (1777-1852) played a central role on the stage of national politics for over forty years. He was secretary of state under John Quincy Adams, Speaker of the House of Representatives longer than anyone else in the nineteenth century, and the most influential member of the Senate during its golden age. In a parliamentary system, he would have undoubtedly become prime minister.