[1] He wrote the words for the songs: "Alice in Wonderland", "In the Wee Small Hours of the Morning", "Any Day Now", "Dear Hearts and Gentle People", "Our Day Will Come", "My Little Corner of the World", "Tower of Strength" and "Seven Little Girls (Sitting in the Back Seat)".

After finishing high school, Hilliard began working as a lyricist in Tin Pan Alley.

[2] During his Broadway years, Hilliard wrote successful scores for both Angel in the Wings (1947) and Hazel Flagg (1953).

The 1954 comedy film Living It Up included his songs "Money Burns a Hole in My Pocket" and "That's What I Like.

[6] Hilliard worked as lyricist and composer with a number of other composers and lyricists over the decades, including Burt Bacharach, Carl Sigman, Jule Styne, Mort Garson, Sammy Mysels, Dick Sanford (né Richard Young Sandford; 1896–1981), Milton DeLugg, Philip Springer, Lee Pockriss and Sammy Fain.