Cambridge, Massachusetts, U.S.A., Cambridge Immigration Law works with clients nationwide on matters related to “green cards'' and U.S. citizenship. Cambridge Immigration Law focuses on the three main steps of marriage-based immigration. the initial green card, the renewal green card, and U.S. citizenship based on marriage to a U.S. citizen. Immigration Lawer Cambridge took all of the stress out of our immigration application. My family had a lot of questions throughout the process, and we felt like Ellen and her team were always happy to help!