Former ARCHITECT senior editor Kriston Capps at CityLab speaks with various construction and design firms about why they are, or are not, on an interested-vendor list for the Dept. of Homeland Security's pre-solicitation for the U.S.–Mexico borderwall. On the list that has reached 350 signatures, many include concrete suppliers, project-management companies, and fence builders. Firms that have articulated an assured lack of interest include Boeing, construction firm Bechtel, and engineering firm AECOM. To read more go to CityLab.