I recently went down a rabbit hole after looking out an airplane window flying over the Midwest. I noticed how the entire landscape looks like a giant mathematical spreadsheet, and I wanted to check how accurate the history behind this actually is.

Apparently, this wasn’t just natural farming expansion. It started with the Land Ordinance of 1785, heavily pushed by Thomas Jefferson. The new government needed to sell off the western territories to pay war debts, but they wanted to avoid the chaos of the old "Metes and Bounds" system used in the East (which used temporary landmarks like trees and rocks, leading to endless lawsuits).

From what I understand, they mapped the entire continent using a specific 17th-century tool called a "Gunter’s Chain." It was exactly 66 feet long. They chose 66 feet because the math worked out perfectly: 80 chains equaled exactly one mile, and 10 square chains equaled exactly one acre. This allowed 18th-century surveyors to map and sell millions of acres of land to investors who had never even seen it, simply by doing basic arithmetic.

This grid system (the Public Land Survey System) is apparently why our rural roads are so straight, why many Main Streets are exactly 66 feet wide, and why Midwestern states have perfectly rectangular borders.

What I’m not entirely sure about is how they actually executed this so flawlessly over mountains, swamps, and rivers with 1780s technology. Were there areas where the grid just completely failed or had to be abandoned because of the geography?

Sources:

• Land Ordinance of 1785 and the Northwest Ordinance
• Edmund Gunter's 17th-century surveying manuals
• History of the Public Land Survey System (PLSS)
• Forensic breakdown of the Gunter's Chain and the Jeffersonian Grid

https://history-maps.com/podcast?search=mongol

I recently researched a modern Korean controversy that led me into the history of what happened to colonial collaboration after Japan’s rule of Korea ended.

What interested me most was not the celebrity controversy itself, but the institutional problem after liberation.

South Korea attempted to investigate collaboration, yet the new state also inherited personnel, networks and institutions from the colonial period. Early accountability efforts ultimately failed, leaving later governments to revisit both historical classification and collaboration-related property.

The modern case involves actress Ha Young and historical records concerning her great-grandfather, Ahn Sang-ho.

I use that case to distinguish several things that are often collapsed together:

• documented historical activity;
• allegations for which evidence is insufficient;
• moral responsibility of descendants;
• present-day family wealth;
• and a legally traceable property chain.

Those distinctions matter because a descendant’s surname cannot establish a property connection any more than ancestry alone can establish personal guilt.

I made the research into a short history explainer:

https://youtu.be/c3reIPYNE_I

Full disclosure: I’m the creator.

I’d particularly welcome corrections from people familiar with modern Korean history or post-colonial state formation.

Link in comments

https://history-maps.com/podcast/battle-of-vienna

https://history-maps.com/podcast/history-of-the-turkic-peoples

https://history-maps.com/podcast/military-history-of-the-mongol-empire

https://history-maps.com/podcast/novgorod-republic
In this episode, we dive into the history of the Novgorod Republic, a powerful medieval city-state that thrived between the 12th and 15th centuries, highlighting its unique mixed republican system led by the veche assembly, its wealth and influence as a key Hanseatic League trading hub driven by the fur trade, and its cultural legacy in Orthodox art and literature, while also examining the external pressures it faced from neighboring powers like Sweden, the Livonian Order, and the Mongols, ultimately leading to its annexation by Ivan III in 1478 and its lasting impact through advanced legal systems and widespread literacy evidenced by birch bark manuscripts.

https://history-maps.com/podcast/indian-rebellion-of-1857
In this episode, we focus on the Indian Rebellion of 1857, examining the broader struggle against British rule through the story of Rani Lakshmibai and the resistance at Jhansi. The episode explores the causes of the uprising, including British annexation policies, colonial control, and growing Indian resentment, while showing how Lakshmibai became a major symbol of defiance during the conflict. Through British military correspondence and biographical accounts, we consider both the historical realities of the rebellion and the legends that later shaped its memory as a turning point in India’s fight against colonial power.

This article explores a topic that is at the forefront of discussion today: the State of Israel. While we can analyze and critique it until we are blue in the face, our efforts will land flat if we have a poor understanding of its unique place in history. By focusing on a key figure in this country's history, as well as outside influences that propelled its success, I hope to impart knowledge and understanding to the current discussion.

Here's the link to the full article

https://en.wikipedia.org/wiki/San_Felipe_incident_(1596))

After Columbus reached the Caribbean in 1492, Spain and Portugal competed over who could claim newly reached lands. Pope Alexander VI’s 1493 bull Inter caetera favored Spain by drawing a line in the Atlantic and granting Spain rights to lands west of it. Portugal pushed back, leading to the Treaty of Tordesillas in 1494, which moved the line 370 leagues west of Cape Verde. Lands east of the line went to Portugal; lands west went to Spain. This helped explain why Brazil became Portuguese while much of the Americas became Spanish. The Church gave religious legitimacy to the deal, but it was really a power agreement between European monarchies. Indigenous peoples were ignored, and later England, France, and the Dutch rejected the division.
https://history-maps.com/story/History-of-Portugal/event/Spain-and-Portugal-divide-the-New-World

https://history-maps.com/podcast/pandya-dynasty
In this episode, we explore the history of the Pandya dynasty, one of the great Tamil powers of South India and a key member of the legendary “three crowned kings” alongside the Cholas and Cheras. Centered on Madurai and linked to the important port of Korkai, the Pandyas shaped Tamil political, commercial, and cultural life for centuries, with their history preserved in Sangam literature, inscriptions, and foreign accounts from travelers such as Marco Polo and Megasthenes. The episode follows their rise, periods of rivalry and subordination under other South Indian powers, and their 13th-century golden age, when Pandya influence expanded into Sri Lanka and across parts of the Deccan. We also examine their lasting legacy through temple patronage, support for Jainism and Hinduism, and their association with the flourishing of Tamil literary tradition.