This book analyses the origins of international law in Latin America, taking as its cradle the legal constructions inaugurated at the Congress of Panama in 1826. Although some of the literature considers the First Pan-American Conference, held in Washington in 1889, to be the initial milestone of the American legal system, we will show that the Congress of Panama laid the foundations for the construction and strengthening of Regional International Law and enshrined relevant principles that are today considered to be pillars of the International Legal Order.