Have you ever wondered how Mother's Day got started? People started honoring mother's a very long time ago. When it first started it was called Mothering Sunday because people celebrated it the fourth Sunday during a time called Lent. Lent is the time before Easter where people think and prepare about the Easter story and what God did for us.
Then 150 years ago a woman named Anna Jarvis, organized a day to raise awareness of poor health conditions in her community, something she thought mother's believed in doing. She called it "Mother's Work Day." 
After Anna Jarvis died, her daughter (also named Anna) wanted to honor all that her mother did. Anna heard her mother say that one day she hoped someone would make a special day just for mothers.
So Anna worked very hard and even talked to presidents and other leaders to try to create a special day just to honor them. By 1914 (almost 100 years ago) a man named Woodrow Wilson signed a bill recognizing Mother's Day as a national holiday.
It just so happens that Anna's mothers' favorite flower was the white carnation and that's why mother's often receive carnations on Mother's Day.