Given the following passage  "Ultimately, World War I created a decisive break with the old world order that had emerged after the Napoleonic Wars, which was modified by the mid-19th century's nationalistic revolutions. The results of World War I would be important factors in the development of World War II approximately 20 years later. More immediate to the time, the partitioning of the Ottoman Empire was a political event that redrew the political boundaries of West Asia. The huge conglomeration of territories and peoples formerly ruled by the Sultan of the Ottoman Empire was divided into several new nations. The partitioning brought the creation of the modern Arab world and the Republic of Turkey. The League of Nations granted France mandates over Syria and Lebanon and granted the United Kingdom mandates over Mesopotamia and Palestine (which was later divided into two regions: Palestine and Transjordan). Parts of the Ottoman Empire on the Arabian Peninsula became parts of what are today Saudi Arabia and Yemen.",  answer the following question. Note that the answer is present within the text.  Question: what is the first time period mentioned?
mid-19th century's