The work La Justicia Constitucional. Su devenir a lo largo de un siglo y medio (1787-1938) , through four extensive volumes, aims to carefully study the evolution of constitutional justice in the century and a half that has elapsed since the North American Constitution of 1787 until 1938, the Austrian Constitutional Court s last year of operation, given that, in 1938, following the invasion of Austria by Nazi troops, the Austrian Federal Republic ceased to exist, and with it, obviously, the Constitutional Court, an institution whose paternity must be attributed to Kelsen.