The term "the United States" has historically been used sometimes in the plural ("these United States") and other times in the singular.
ðə tˈɜːm "ðə juːnˈaɪɾᵻd stˈeɪts" hɐz hɪstˈɔːɹɪkli bˌɪn jˈuːzd sˈʌmtaɪmz ɪnðə plˈʊɹɹəl"ðiːz juːnˈaɪɾᵻd stˈeɪts"ænd ˈʌðɚ tˈaɪmz ɪnðə sˈɪŋɡjʊlɚ.