On War
From 1832 to 1834, following Clausewitz's unexpected death from cholera in 1831, she edited and published several of his books, including his most famous one, "On War". Throughout their correspondence, Marie insisted that Carl send her his drafts and notes for safekeeping. He was known to have an unorganized writing process that would often lead to lost papers and unfinished ideas. In fact, when Carl was writing "On War", Marie acted as the researcher and copywriter for the book. Marie's handwriting can be found on some of the pages of the "On War" manuscript, listing notes and references. Additionally, Brühl wrote a preface to "On War". In the summer of 1832, less than a year after Carl's death, a publishing house in Berlin had put out announcements advertising the upcoming publication of "On War". With the help of her brother, Marie transcribed drafts and inserted changes for "On War" in a manner of months.