[the map above shows nations that seceded peacefully or violently from the UK.]

Here’s a list of countries that seceded peacefully:
1777 Vermont from New York/USA (rejoins Union in 1791 1791)

1789 11 states of USA seceded from the Union, but NC, RI re-joined in 1789-1791

1831 Belgium from the Netherlands

1857-1987 (gradual) New Zealand from UK
1862 Liberia from USA

1867 Canada from UK
1901 Australia from UK

1902 Cuba from USA
1905 Norway from Sweden
1917 Finland from Russia
1934 South Africa from UK
1944 Iceland from Denmark
1946-1980 about 62 colonies of European countries
1946 Philippines from USA

1949 Chinese Civil War is resolved by splitting Taiwan from mainland China

1961 Syria from United Arab Republic

1965 Singapore from Malaysia
1986 Marshall Islands and Micronesia from USA
1989 Eastern Bloc nations from Warsaw Pact
1991 Slovenia, Macedonia from Yugoslavia
1991 each of the republics of the USSR
1993 Czechoslovakia split into Czechia and Slovakia
1994 Palau (a Pacific island) from USA
2006 Montenegro from Yugoslavia
2019 UK from EU

Here are a couple ancient examples:

Secession of Lot’s herdsmen from Abraham’s herdsmen

930 BC Ten tribes of Israel split from Judah.  Judah survived much longer.

395 AD eastern and western Roman empire split.  Eastern side survived 1000 more years.

Exoduses: 

Most Americans are descended from people who migrated to America in mass movements to preserve their religious liberty from a place of tyranny.  Today, there is no place left on Earth where we may peacefully create a new colony that would allow such religious liberty.  Our only option is to secede and make some of our own states free from the tyranny of the Left.

Noah from the world

Abraham from Ur

Lot from Sodom

Israel from Egypt to Canaan

Jews from Babylonian Empire to Jerusalem

1620-1640 Great Migration of Puritans from England.

from Plymouth Colony (for religious freedom) to Rhode Island

Huguenots from France, German Protestants from Catholic oppression to America

1783 Loyalists from USA to Canada

1846 Mormons from America

1900s Jews from the nations to Israel

American Secessions:

1774 Every county in Massachusetts except Boston throws off the king’s governance, which is never restored.

1775 May 20 North Carolina declares independence from British North America/Great Britain (if most historians are correct)

1776 March 26 South Carolina secedes from from British North America/Great Britain

1776 May 4 Rhode Island secedes from British North America/Great Britain

1776 May 15 Virginia secedes from British North America/Great Britain

1776 June 15 New Hampshire secedes from British North America/Great Britain

1776 June 15 Delaware secedes from Pennsylvania and from British North America/Great Britain

1776 July 2 The remainder of the 13 colonies secede from British North America/Great Britain (leaving behind Canada, Florida, Bermuda, the British Caribbean, etc). Florida was British at this time.

1776 July 6 Maryland issues its own declaration of independence.

1777 Vermont from New York and from the USA (rejoins Union in 1791)

1789 11 states left the 13-state union, leaving behind NC & RI, but NC & RI joined the seceded states within two years.

1836 Texas (being populated mostly by Americans) secedes from Mexico and secedes from the Mexican state of Coahuila y Tejas.

1846 California secedes from Mexico: On June 15, 1846 the Bear Flag Manifesto was declared (declaring independence from Mexico). On July 7, 1846 the US flag was raised and annexation of California was declared.

1848 secession of southwestern US from Mexico acknowledged by Mexico

1853 Gadsden Purchase: southern Arizona sold by (peacefully secedes from) Mexico and given to US.

1860 South Carolina secedes. President James Buchanan decides not to fight the secession.

1861 Multiple states secede. President Lincoln inaugurated March 4, Union invades May 24.

1862 secession of Liberia from the USA recognized by US Congress

1867 Alaska sold by (peacefully secedes from) Russia and given to US

1867 after the Southern states rejoined the Union, Congress ejected them from the Union so that they would be subject to military authority for Reconstruction.

1902 Cuba secedes from USA (4 years after Spanish-American War)

1946 Philippines secedes from USA

1986 Marshall Islands and Micronesia secede from USA
1994 Palau, a Pacific island, secedes from USA

There have been more than 50 independence referendums around the world since the middle of the 19th Century when Texas, Virginia and Tennessee—albeit unsuccessfully—voted to leave the USA. A handful of plebiscites were held in each decade after 1945, but most independence referendums were held after the break‐down of communism. Most have resulted in majorities for independence.