This dissertation examines the dialectical relationship between informal dwellings and the formation of the modern state of Iraq in the 20th century. It focuses on the settlements that grew in and around Baghdad in the decades following Iraq's independence in 1932. Individuals from agricultural estates from the largely Shi'i southern provinces fled by the thousands to Baghdad, and by 1956, around half of the houses recorded in Greater Baghdad were registered as informal dwellings constructed of reed mats and mud. And, yet, these settlements have not been central to architectural, urban, or political histories of Iraq—even though migrant lifeworlds and informal settlements were arguably the predominant features of mid-20th century Baghdad. Migrants formed the backbone of the human infrastructure that sustained the building of an efficient, modern state. Where informal laborers worked in construction, others were employed as low-ranking policemen, soldiers, and bureaucrats by the state. Informalization of the capital, thus, accompanied the formalization of state institutions. From this obscured history, my research asks: how were surplus populations like rural migrants disciplined upon reaching the capital? How did the historically imagined territory of Baghdad exclude informal dwellings? What types of knowledge were produced about illegal settlements through the mediums of film, photography, architectural drawings, and surveys? How were oil surpluses used in urban planning interventions to territorially integrate migrants into a global debt economy? And, finally, how did these informal settlements, in turn, shape the governmental apparatuses of the state?