Sovereign State

this graph was created in Loocker studio,Tableau and R:

What you should know about this indicator
For the years until 1919, Correlates of War considers a country a sovereign state if it has a population of at least 500,000 people, and is diplomatically recognized by France and the United Kingdom.
For the years after 1919, a country is considered a sovereign state if it either at any point was a member of the League of Nations or the United Nations, or had a population of at least 500,000 people and was diplomatically recognized by at least two major powers.

This data set contains the list of states in the international system as updated and distributed by the Correlates of War Project. These data sets identify states, their standard Correlates of War “country code” or state number (used throughout the Correlates of War project data sets), state abbreviations, and dates of membership as states and major powers in the international system. Version 2016 extends the temporal domain of the collection through December 2016.

The Correlates of War project includes a state in the international system from 1816-2016 for the following criteria. Prior to 1920, the entity must have had a population greater than 500,000 and have had diplomatic missions at or above the rank of charge d’affaires with Britain and France. After 1920, the entity must be a member of the League of Nations or the United Nations, or have a population greater than 500,000 and receive diplomatic missions from two major powers.

All data and visualizations on Our World in Data rely on data sourced from one or several original data providers. Preparing this original data involves several processing steps. Depending on the data, this can include standardizing country names and world region definitions, converting units, calculating derived indicators such as per capita measures, as well as adding or adapting metadata such as the name or the description given to an indicator.

At the link below you can find a detailed description of the structure of our data pipeline, including links to all the code used to prepare data across Our World in Data.