The Knights of the Golden Circle gain power in the American South and industrialise the area during the 1850 and 1860s, They increase their autonomy and then instead of engaging in civil war with the north they invade and/or unite with various slave holding powers in the Caribbean. They also unite with Mexico and the rest of Central America. The Golden Circle gains a huge population and so has mandatory conscription giving it a huge army and navy. The northern non-slave trading USA decides to invade the Golden Circle and is defeated during a great naval war in the Caribbean. The Golden Circle still trades slaves with African nations gaining great profit for the both African chieftains and leaders as well as Golden Circle traders.
Ethnic tensions surrounding the mainly white, Hispanic and black populations causes in-fighting which is increased for religious tensions of Catholicism vs Protestantism leading to sectarian violence. The capital of Havana is the scene of a slave uprising which is crushed by the army and the nations of Golden Circle decide to soften slavery by making it so that slaves can be freed after they reach old age. They also give equal support to both Catholics and Protestants as well as both English and Spanish languages which are used throughout the Golden Circle whilst Native American languages and Creole languages are restricted and their speakers are punished.
Due to the size and wealth of the Golden Circle it becomes a world power and influences the British Empire by allowing it to re-institute the slave trade. The USA decides to invade the Golden Circle but is defeated by both Britain and the Golden Circle. America is left as a poor backwater whilst the Golden Circle increases in power.
During WW-I the Golden Circle manages to defeat Germany with British help. The Circle then helps the white tsarists to defeat the reds during the Russian civil war. Due to their being no USSR and no Communist threat Hitler never rises to power and neither do the Communists so Germany becomes an unstable backwater forgotten by the other major powers. A cold war arises between slave trading states of Africa, the Golden Circle and the British Empire which survives against anti-slave trading states of the USA, France and Nationalist China.
Russo-Japanese war still occurs but World War 2 does not. However, Japan still invades Manchuria and keeps it forever but none of this leads to any larger conflicts.
The world today is far more interconnected and mixed due to slave trading, Russia becomes much more like Britain and the USA becomes far more wealthier and more tolerant.
The world is far more peaceful as it is under British, Golden Circle and Russian dominance in modern times. However, slavery still exists and the Spanish racial caste system is the ruling factor for most people.
The Korean War never happens because Communism never exists and McCarythism is more directed towards anti-slavery activists rather than other more left wing or liberal peoples. Korea also remains under Japanese control and suffers a huge genocide which almost wipes out Korean culture and destroys the Hangul writing system
The battle of Chamdo still occurs. However, with help from the Golden Circle and the British empire, Tibet manages to repel the Chinese invasions backed by France and other European powers.
The cultural revolutions happen in France and China and so do the hippie movements, this very similar to our timeline but the focus is mainly anti-slavery. Anti-slave movements are set up in the Golden Circle to help free slaves. The Golden Circle actively bombs and sets up pro-slavery and pro-Golden Circle dictators throughout South America but this ends with mass uprisings in these countries of guerrilla forces who pay for mass slave uprisings in the Golden Circle and also try to create division through usage of sectarian violence between Catholics and Protestants.
Israel does not exist in this timeline and Palestine is under British control so none of the Arab-Israeli wars happen. However, revolution movements in British colonials do occur but apart from India, the majority of them fail
Countries which exist because of these events:
Golden Circle: Knights of the Golden Circle come to power and form largest non-partisan democracy
Republic of China - no USSR and thus no influence of Communism for Mao Zedong who remains a pig farmer
Russian Empire - due to the failure of the Bolsheviks
British Empire - due to there being no World War 2 Britain manages to keep most of its empire.
Countries which do not exist:
Pakistan remains part of India along with East Pakistan/Bangladesh
South Africa but as a dominion of the British Empire
Ireland kind of