treasury promotion honors non-President Alexander Hamilton . ( CNN ) -- Beware learning American history through Groupon promotions . Online coupon company calls Groupon `` undeniably one of our greatest presidents '' Hamilton , who 's on the $ 10 bill , was Groupon Presidents Day secretary but not president . `` Joke ? We 'd never joke about saving $ 10 ! # AllKindsOfSerious '' Alexander Hamilton tweets .
treasury promotion honors non-President Alexander Hamilton . Online coupon company calls Groupon `` undeniably one of our greatest presidents '' Hamilton , who 's on the $ 10 bill , was Groupon Presidents Day secretary but not president . `` Joke ? We 'd never joke about saving $ 10 ! # AllKindsOfSerious '' Alexander Hamilton tweets .