Mother's Day's origins date back to the Middle Ages.
Back in then it was common for children as young as 10 years old to leave home but they had an opportunity for them to meet their families again. The custom developed of allowing people who had moved away to return to their home or mother churches on the fourth Sunday of Lent.
This led to the creation of Mothering Sunday and its date changes every year.
In the US however, the idea came about when Anna Jarvis held a small memorial on 12 May 1907 for her own mother and it wasn't long before most places in America began observing the day. In 1914, the 28th US president Woodrow Wilson made it a national holiday, celebrating it on the second Sunday of May.