This dissertation examines the first three decades of a missionary encounter that began under the auspices of the Congo Inland Mission (CIM – later renamed as Africa Inter-Mennonite Mission [AIMM]) in Belgian Congo. As Africans, North Americans, and Europeans entered into relationship with each other through mission, they developed an identity as global Mennonites. They began to embrace a catholic ecclesial imagination – that is, a commitment to shared membership within the church as a political body capable of transcending competing claims of race, ethnicity, gender, or nation-state. Using both an ecclesiological lens of analysis and a global history framework, this dissertation traces the ways in which ecclesial institutions, practices, discourses, and performances functioned to support or undermine a social imagination that embraced expatriate missionaries and local believers within a single church, in both its local/congregational and trans-local manifestations. During the period covered by the dissertation, expatriate and Congolese Mennonites struggled to define what the church was, and to determine who could participate in it and how. Factors that helped to promote a shared ecclesial imagination among Congolese and expatriate believers included an inter-denominational vision, faith mission principles and practices, Pentecostal revivalism, a Mennonite congregational polity, shared experiences of work and worship, and friendships that crossed boundaries of race and gender. However, CIM missionaries’ assertions of ethnic Mennonite control over mission strategy and structure, and their complicity with colonial labor exploitation, promoted a two-tiered understanding of the church that entrenched racial segregation and squelched the aspirations of white missionary women and Congolese evangelists. An ecclesiological lens of analysis thus offers new insights into the relationship between missions and colonial regimes, into the role of mission in American Mennonite denominational formation, and into the ...