California, Vermont, Texas, Hawaii
While this question asks for four, it should be noted there were other republics that joined the Union:
Republic of West Florida (Approx 3 months before the US annexed it.)
Republic of South Carolina (Existed for almost two months before the formation of the Confederacy) (But, for the sake of the question, they were previously part of the union. You could count, if you want to, the first time S.C. declared itself a republic. On 3/26/1776, they declared their independence from Great Britain, more than 3 months before the U.S. Declaration of Independence. Whether it was recognized or not is a different matter. That being said, the California Republic was not recognized by any nation either and lasted less than a month.)
They were independent republics
Commonwealth of Independent States
Before achieving statehood, several territories in the United States were recognized as republics. Notably, Texas was an independent republic from 1836 until it joined the Union in 1845. Additionally, California briefly declared itself a republic in 1846 during the Bear Flag Revolt before becoming a state in 1850. However, Texas is the most prominent example of a territory that functioned as a republic before statehood.
The three former Soviet republics that were the first to join the Commonwealth of Independent States (CIS) are Belarus, Kazakhstan, and Russia. They signed the agreement establishing the CIS on December 8, 1991, shortly after the dissolution of the Soviet Union. This alliance aimed to promote cooperation in various areas, including economic and political matters, among the newly independent states.
Nations that had been colonies of Britain withdrew from the British Commonwealth to form independent republics. This included the United States, as well as several countries in Africa.
They were independent republics
Texas was in independent republic before statehood.
Texas was once an independent country before joining the United States as a state.
Commonwealth of Independent States
Vermont was briefly an independent republic before joining the newly-formed United States in 1791.
Before achieving statehood, several territories in the United States were recognized as republics. Notably, Texas was an independent republic from 1836 until it joined the Union in 1845. Additionally, California briefly declared itself a republic in 1846 during the Bear Flag Revolt before becoming a state in 1850. However, Texas is the most prominent example of a territory that functioned as a republic before statehood.
That would be the Commonwealth of Independent States, CIS.
Some of the Greek city-states were republics, Athens for example.
The Commonwealth of Independent States also known as the CIS was formerly known as The Russian Commonwealth. The organization was regional and was formed after the breakup of the former Soviet Union and its participating countries were former Soviet Republics.
CIS stands for Commonwealth of Independent States, which is an association of former Soviet republics. It is not a nationality, but rather a geopolitical organization. Members include countries such as Russia, Ukraine, Belarus, and Kazakhstan, among others.
Yes, they are. All six of the former Yugoslav republics (Slovenia, Croatia, Bosnia, Montenegro, Serbia and FYR Macedonia) are recognized as independent states. The secessionist (former Serbian autonomous province of) Kosovo also declared independence. It is recognized by 76 out of 193 UN member states. Serbia disagrees and considers Kosovo to be its rebel province.
Nations that had been colonies of Britain withdrew from the British Commonwealth to form independent republics. This included the United States, as well as several countries in Africa.