Nursery rhymes and Childrens Poetry often reflect events in history. In addition to historical event they were also invented as a way of spreading gossip about royalty. Originally they where taught in nursery but nowadays they are taught in places such as Sunday school, pre-school / kindergarten and day care. Learning poems in the form of Nursery Rhymes can assist in the development of counting skills (for example 1, 2, Buckle my shoe. 3, 4 Shut the door. 5, 6 Pick up sticks. 7, 8 Lay them straight. 9, 10 A big fat hen! ). 

Mother Goose is a popular selection of Rhymes 

LanternTree.com is Another site contains Nursery Rhyme lyrics.