kˈɜːtʃhɔf wʌz ˌɪnstɹəmˈɛntəl ɪn dᵻfˈaɪnɪŋ ðə kˈɑːnsɛpt ʌv mˌɛsoʊɐmˈɛɹɪkə, ɐ kˈʌltʃɚɹəl ɹˈiːdʒən ʃˈɛɹɪŋ ɐ nˈʌmbɚɹ ʌv kˈɑːmən kˌæɹɪktɚɹˈɪstɪks θɹuːˈaʊt mˈoʊst əv pɹˈiːkəlˈʌmbiən hˈɪstɚɹi, dʒˌɪəɡɹˈæfɪkli dᵻfˈaɪnd æz sˈɛntɹəl ænd sˈʌðɚn mˈɛksɪkˌoʊ ænd nˈɔːɹðɚn sˈɛntɹəl ɐmˈɛɹɪkə.
Kirchhoff was instrumental in defining the concept of Mesoamerica, a cultural region sharing a number of common characteristics throughout most of pre-Columbian history, geographically defined as central and southern Mexico and northern Central America.