ˌɔn sɛptˈɛmbɚ twˈɛnti sˈɪks, nˈaɪntiːnhˈʌndɹɪd θˈɜːɾi nˈaɪn, ˌɛsˈeɪtʃ sˈɛvənti θɹˈiː wʌz ɛkstˈɛndᵻd ˈiːst tə pˈoːɹt ˈɑːɹθɚ, ɹᵻplˈeɪsɪŋ ˌɛsˈeɪtʃ tˈuːhˈʌndɹɪd twˈɛnti ˈeɪt, ænd ðə stɹˈɛtʃ fɹʌm wˈɪni tʊ ˈænɐhjˌuːæk ɹᵻplˈeɪst pˈɑːɹt ʌv ˌɛsˈeɪtʃ wˈʌnhˈʌndɹɪd twˈɛnti fˈaɪv.
On September 26, 1939, SH 73 was extended east to Port Arthur, replacing SH 228, and the stretch from Winnie to Anahuac replaced part of SH 125.