**Ernesto Castañeda**

Department of Sociology, American University, Washington, DC 20016, USA; ernesto@american.edu

Received: 9 November 2020; Accepted: 9 November 2020; Published: 23 November 2020

**Abstract:** This paper provides some historical context to understand border formations. By comprehending how our present system of borders and exclusions function, we can gain a new appreciation for migration. Moreover, it presents arguments for open borders to counter anti-immigrant policies, includes short summaries of relevant research, as well as for each article included in this Special Issue. Together, these articles show how more welcoming policies towards immigrants, refugees, and asylum seekers do not threaten popular sovereignty but, conversely, strengthen both democracy and local rights.

**Keywords:** border walls; fences; limited migration; open borders; free movement; regionalism; localism
