Significant progress by experiments trying to detect the Global 21cm signal from neutral hydrogen in the intergalactic medium during the Dark Ages, Cosmic Dawn, and the Epoch of Reionization (z>6) has increased the attention on this measurement from the Astrophysics, Particle Physics, and Cosmology communities. In particular, the EDGES experiment has reported an absorption feature that could correspond to the Global 21cm signal, but which is significantly deeper than theoretical models and has other characteristics that depart from expectations. Instrumental calibration, foreground removal, radio-frequency interference, and ionospheric effects remain as issues that transform this measurement into a daunting experimental effort. In light of the above, we will host the Second Global 21cm Workshop at McGill University on October 7th-9th, 2019. This workshop will serve as a forum to discuss recent progress from all the Global 21cm experiments. We will have talks about theory, data analysis, and, above all, instrumental development and field work. We will also host several discussion sessions expecting the most important aspects and concerns being raised and addressed.