in thematics (Stamatatos, 2009). Several studies agreed on assigning the 158 disputed works in their entirety to Madison, while Papers 18-20 have gener- 159 ally been found to be written jointly by Hamilton and Madison as Hamilton 160 claimed, even though some researchers tend to attribute them to Madison 161 alone (Jockers and Witten, 2010; Meyerson, 2008; Adair, 1974). 162 We analyzed a dataset composed of a randomly selected number of texts 163 of certain attribution by Hamilton and Madison, plus all the disputed and 164 jointly written essays. We then computed a distance matrix related to the 165 described dataset according to the FCD distance, and performed on the 166 matrix a hierarchical clustering which is by definition unsupervised. A den- 167 drogram (binary tree) is heuristically derived to represent the distance ma- 168 trix in 2 dimensions through the application of genetic algorithms (Cilibrasi, 169 2007; Cilibrasi and Vit´ anyi, 2005). Results are reported in Fig. 2, and 170 have been obtained using the freely available tool CompLearn available at 171 Cilibrasi et al. (2002). Each leaf represents a text, with the documents which 172 behave more similarly in terms of distances from all the others appearing as 173 siblings. The evaluation is done by visually inspecting if texts written by the 174 same authors are correctly clustered in some branch of the tree, i.e. by check- 175 ing how well the texts by the two authors can be isolated by ‘cutting’ the tree 176 at a convenient point. The clustering agrees with the general interpretation of 177 the texts: all the disputed texts are clearly placed in the section of the tree 178 containing Madison’s works. Furthermore, the three jointly written works 179 are clustered together and placed exactly between Hamilton and Madison’s 180 10