For at least the next decade, the only opportunity to study the atmospheres of terrestrial exoplanets will be scrutinize these worlds when they transit nearby small stars. There are 412 mid-to-late M-dwarfs within 15 parsecs, yet we know surprisingly little about them, let alone their attendant planets. I will discuss recent findings from the MEarth Project and TESS Mission, which seek to discover the most spectroscopically accessible terrestrial exoplanets. Our recent discoveries of a rocky worlds transiting the nearby small stars LTT1445, LHS1140, and LHS3844 provide unprecedented opportunities to ask whether these worlds have retained their atmospheres and, if so, what molecules are contained therein. In our planetary quest, MEarth, TESS, and complementary spectroscopic observations have sharpened our understanding of the evolution of magnetic phenomena of these low-mass stars, and hence the stellar environment in which these planets may wither or thrive.