As the summer scorcher continues, National Ice Cream Day is coming to to cool us all down on July 21. The beloved food holiday celebrates the cold, sugary treat that can't be beat, and a plethora of brands are giving away free or discounted ice cream to celebrate. The national holiday takes place every third Sunday in July, which is also known as National Ice Cream Month. It's all thanks to President Ronald Reagan who signed a proclamation 40 years ago, partly due to his love of the frozen delight, designating the national month and holiday.In 1984, President Ronald Reagan designated July as National Ice Cream Month and the third Sunday of the month as National Ice Cream Day.Ice cream became popular throughout the world in the second half of the 20th century after cheap refrigeration became common. There was an explosion of ice cream stores and of flavours and types.Augustus Jackson is often called the “father of ice cream.” This black entrepreneur was a chef at the White House before moving on to open his own confectionary shop in Philadelphia, Pennsylvania. There he sold quarts of eggless ice cream for $1 a piece to other black-owned parlors in the city.