ˌɛsˈeɪtʃ sˈɛvənti tˈuː wʌz ɚɹˈɪdʒɪnəli pɹəpˈoʊzd ˌɔn ˈɔːɡəst twˈɛnti wˈʌn, nˈaɪntiːnhˈʌndɹɪd twˈɛnti θɹˈiː fɹʌm kjˈuːɹoʊ tə kˈɑːɹmaɪn, ɐbsˈoːɹbɪŋ pɹˈiːviəsli dˈɛzɪɡnˌeɪɾᵻd ˌɛsˈeɪtʃ θɹˈiː bˈiː. ˌɔn mˈɑːɹtʃ sˈɛvəntˌiːn, nˈaɪntiːnhˈʌndɹɪd twˈɛnti fˈoːɹ, ɪt wʌz ɛkstˈɛndᵻd saʊθwˈɛst tə jˈɔːɹktaʊn.
SH 72 was originally proposed on August 21, 1923 from Cuero to Carmine, absorbing previously designated SH 3B. On March 17, 1924, it was extended southwest to Yorktown.