This volume presents the up-to-date results of investigations into the Asian origins of the only two language families of North America that are widely acknowledged as having likely genetic links in northern Asia. It brings together all that has been proposed to date under the respective rubrics of the Uralo-Siberian (Eskimo-Yukaghir-Uralic) hypothesis and the Dene-Yeniseian hypothesis. The evolution of the two parallel research strategies for fleshing out these linguistic links between North America and Asia are compared and contrasted. Although focusing on stringently controlled linguistic reconstructions, the volume draws upon archaeological and human genetic data where relevant.