Lately I have been very interested in the history of the Afrikaner people in South Africa, and have done extensive research on everything from their arrival with the establishment of the Kaapkolonie in 1652 by the Dutch East India Company until the end of the Boer Wars and the history of the Union of South Africa. Something that always made me wonder about a situation like this is the possibility/plausibility of something like this happening in North America.
After some brief research on the Dutch Colony of "Nieuw Nederland", I have determined that the POD would have to be at the end of the Second Anglo-Dutch War, where at the Treaty of Breda, the Netherlands returns Surinam to the British, however unlikely, instead of annexing Surinam and letting New Netherland go.
The Dutch originally gave up New Netherland because they captured Surinam and preferred the resources produced by Surinam over the colony in modern day New York. I can't think of a plausible way the Dutch would give up Suriname, so I'll let you guys figure that out.
Timeline:
So, here we are. 1667, the Dutch sign the Treaty of Breda, relinquishing occupied Surinam back to the Brits and keeping control of New Netherland. Not much changes besides the obvious language barrier between Modern New York and TTL's New Amsterdam. The big change comes in 1776, with the revolution of the Thirteen American Colonies. With New Netherland firmly under Dutch control, it remains neutral for the first couple years but during the war, animosity between the Dutch and British begins to grow and with the outbreak of the Anglo-French War in 1778, tensions erupt in the Dutch Republic. A series of revolutions and civil wars occur between the Pro-British forces and the Pro-French and American forces, just like OTL. Except, in TTL, the colony in New Amsterdam is taken over by Pro-British forces, leading to a subsequent French-American invasion of the colony. Shortly after the end of the American Revolutionary War, the Americans relinquish control of the territory back to the Dutch, with the Dutch-American Alliance being signed in 1789.
The re-established colony doesn't last for very long, as with the beginning of the Napoleonic Wars and the establishment of the Batavian Republic in 1803, things start to get crazy. The French decide against selling Louisiana for now, instead offering the Americans all of Canada if they join the war. This convinces the Americans, who say they will be ready for war by 1807. (I forgot to mention that by now, New Netherlands encompasses most of Modern Day New England). In 1805, the British invade New Netherland as a preemptive strike to prevent an American annexation of the region. This leads to the Second Anglo-American War, also known as the War of 1805. The Americans are unprepared for the war, but the French manage to score a decisive Victory at the Battle of Trafalgar, leaving the British Royal Navy in tatters. British reinforcements have trouble arriving in Canada, allowing for a swift American seizure of Ottawa and Montreal.
The Americans are pushed out of Ottawa by Canadian militias and British forces but Pro-American French militias managed to seize control over most of settled Quebec, including Quebec City and Trois-Rivières. American and Quebecois forces expel the Canadians oncemore from Ottawa in January of 1807, and New Amsterdam falls to the Americans on March 23rd, 1807. However, the Americans face a war with the Indians in Mississippi, forcing them to pull back from Ottawa and leaving the French militias to themselves. The Quebecois sign a treaty with the British, granting them heavy autonomy and promise for a future dominion separate from the rest of Canada. The British retake New Amsterdam from the small American garrison in October of 1807, but the Americans are able to stop the British from advancing further. Finally on May 24th, 1808, the war ends with the signing of the Treaty of Ottawa, and no border changes occur, however British ships are forced to stop capturing American sailors and Britain is forced to pay reparations. With New Netherlands firmly in their hands, the British are able to fully annex the colony and form a new colony under the name "New England".
Although officially the Dutch are granted British citizenship, Dutch is forbidden to be spoken in public and teaching Dutch is banned in schools. Persecution of the Dutch locals begins to hit a boiling point, with the "Great Trek", as thousands of Dutch citizens pack up their things and march West, headed for the vast underpopulated French colony of Louisiana.
They arrive in 1810 after a long journey, and establish three settlements along the Mississippi river in the Modern US state of Iowa. The three settlements become known as "Kappburg" after their leader Giel van de Kapp, "Riveria" after the River, and "Worstelen" or "Struggle" in Dutch. By 1835, more settlements have developed as more Dutch refugees flee their home which is now being colonized by Canadians and Englishman. The forefathers of the Great Trek announce the creation of the "Amerikaner Republiek" with its capital in Kappburg. The new Republic encompasses much of Eastern Modern Day Iowa. This new country worried the growing American state, who was negotiating with the new restored Bourbon monarchy in France about purchasing Louisiana. After pressure from the Americans, the French sent an expedition to the new Republic to disarm its citizens and end its sovereignty. The small force of around 2,000 is decisively defeated the Battle of Trekland, and is routed. The French are angered by the Dutch, and prepare a full invasion. The Dutch collect ammunition and guns from the dead Frenchman and prepare to defend their new home.
The First Franco-Amerikaner War begins in December 1835, with the French siege of Kappburg and subsequent fall of Kappburg. The government flees to the second largest city, Worstelen, and prepares to coordinate a resistance, as guerrilla fighters harass the supply lines of the 5,000 strong French force. The Amerikaners manage to gather up around 1,000 men to resist the French invasion. The French march on Worstelen, but are ambushed in the forest outside the city, leading to a shocking and crushing defeat of the force. around 1,400 Frenchman are killed, and another 2,000 wounded. Only 120 Amerikaners died in the battle.
The Franco-Amerikaner War ended in February of 1836, with the French capitulation at Kappburg, and the removal of all French troops from the Republic.
The Americans purchased Louisiana from the French, claiming that the Amerikaners were not sovereign and were apart of America. This attitude changed however, when the Amerikaners send a Kommando to aid the American forces in both the Mexican-American War and the Third Anglo-American War. Amerikaners fought bravely at the Battle of Cerro Gordo in Veracruz and the Battle of New York.
When the Americans annexed New England, they renamed it New Netherland in honor of the Amerikaners who fought to retake the land. New York was once more renamed to New Amsterdam, however most of the Dutch remained in the Midwest, not wanting to return to a place that most of them don't remember.
After a weird limbo state for about 40 years, in 1876, the Treaty of Worstelen is signed, and the Amerikaner Republic is annexed into the United States as the "State of Kappburg". The locals are allowed to retain their Dutch language and are granted heavy autonomy as a state is.
In the modern day, the Dutch they speak has evolved into a mix of Dutch and English, dubbed "Amerikaans", similar to "Afrikaans" in South Africa. The State of Kappburg is an odd remnant of Colonial times in America, with a random dutch speaking state in the middle of Anglo dominated America. New Amsterdam is one of the largest cities in the US, despite remaining mostly English speaking. All of the remnants of the New Netherland colony are erased, with the creations of the States of Connecticut, Maine, Massachusetts, and Vermont. OTL's New York State is actually New Amsterdam.
I know its pretty shitty, so comment your theories down below. Thanks.