American teacher Patty Smith Hill famously wrote the words to which well-known song?

Patty Smith Hill (March 27, 1868 – May 25, 1946) was a composer and teacher who is perhaps best known for co-writing, with her sister Mildred Hill, the tune which later became popular as "Happy Birthday to You". She was an American nursery school, kindergarten teacher, and key founder of the National Association for Nursery Education (NANE) which now exists as the National Association For the Education of Young Children (NAEYC).

Patty Hill is perhaps best known as the sister of Mildred J. Hill, with whom she is credited as co-writing the tune to the song "Good Morning to All". The tune became even more popular as "Happy Birthday to You" during the 20th century. Hill and her sister Mildred wrote the song (Mildred wrote the tune; Patty wrote the original lyrics) while Mildred was a composer of songs and Patty was principal at the Louisville Experimental Kindergarten School.

"Happy Birthday to You", also known as "Happy Birthday", is a song traditionally sung to celebrate a person's birthday. According to the 1998 'Guinness World Records', it is the most recognized song in the English language, followed by "For He's a Jolly Good Fellow". The song's base lyrics have been translated into at least 18 languages.