From "Rock a Bye Baby" to "London Bridge is Falling Down," traditional lullabies and nursery rhymes have a long history of controversy with unclear meanings. As with many oft-told theories, the real meaning may never been known with certainty.
Though the date of publication conflicts with the theory, one idea behind "Rock a Bye Baby" purports that it was the first poem written on American land in the 17th century. This theory asserts that the writer observed native people rocking their babies to sleep in birch-bark cradles tied to the branches of a tree. Others theorize that the lullaby captures events preceding the Glorious Revolution, of which the baby in the song was the offspring of James VII, a real child who may have been smuggled into the delivery room from another parent so that James would have a Roman Catholic heir. In this theory, the wind represents Protestant forces, whereas the cradle represents the royal House of Stuart.
A common interpretation of "London Bridge is Falling Down" is that it referenced immurement, the act of entombing a person within a structure. In hopes that doing so would guarantee the stability of a structure, numerous people starved to death after being enclosed in castles, churches and at least one bridge in Bremen, Germany. The song, a likely ode to the children whose lives ended in order to be "eternal watchmen," generated a children's game by the same name. To play, two children sing the song while holding hands in an arch that other children run under, leaving the last child trapped when the song ends.