Encoding an XML Tree model for my corpus

I work on a project called “Digital edition of historical manuscripts” which aims to diffuse on a public platform multiple corpora that all have one thing in common: they are ego documents, which refer to personal writings, memoirs, correspondence and documents alike. My job, personally, is focused on one corpus, a correspondence from a century ago, written regularly by a French, Nobel Peace Prize winning senator to an American friend, president of Columbia University and future Nobel Peace Prize winner, during World War I. Those letters depict his vision of war and its consequences, as a pacifist, non-combatant, political and...