The American Mercury on The Leo Frank Trial: Week One provides a detailed account of the first week of the 1913 trial of Leo Frank for the murder of 13-year-old Mary Phagan, as covered by The American Mercury in a centenary series originally published in 2013. Below is a description of the Leo Frank case, tailored to incorporate key points from the first week of the trial as described in the source, maintaining the context of your request for an introduction to the case and aligning with the free speech video-sharing platforms discussed earlier.