Terra Tempus Daily #112 — September 20, 2026

Round 1

Gadsden Purchase

Gadsden Purchase · 1853 · 19th Century

Why there: The flat, low-elevation desert south of the Gila River offered the only practical grade for a transcontinental railroad avoiding the Rockies, and it still lay in Mexican hands after the 1848 border was drawn just north of it.

Why then: Coming right after the Mexican-American War and amid the railroad boom, the U.S. was flush with expansionist ambition and eager to build a southern rail line, while a cash-strapped postwar Mexico was willing to sell for ten million dollars.

• The Gadsden Purchase (1853) transferred land from Mexico to the United States for $10 million.
• It secured territory for a planned southern transcontinental railroad route.
• It established most of the present-day border of Arizona and New Mexico with Mexico.

Round 2

Battle of Montgisard

Battle of Montgisard · 1177 · Medieval

Why there: Montgisard lay on the coastal route between Egypt and the Crusader-held city of Jerusalem, so Saladin's army had to pass through this vulnerable corridor near Ramla to strike at the heart of the Kingdom of Jerusalem, letting Baldwin IV intercept it there.

• This battle saw the 'Leper King' of Jerusalem, Baldwin IV, defeat the sultan Saladin.
• Saladin barely escaped with a fraction of his army.
• It was fought near Ramla, in present-day Israel.

Round 3

Battle of the Maureaco Fields

Battle of the Maureaco Fields · 451 · Antiquity

• The Battle of the Catalaunian Plains (451 CE) pitted the Roman general Aetius and his Visigothic allies against Attila the Hun.
• The Visigothic king Theodoric I was killed during the battle.
• The clash halted Attila's westward advance into Gaul.

Round 4

Battle of Rocroi

Battle of Rocroi · 1643 · Early Modern

Why there: Rocroi sat on France's vulnerable northeastern frontier along the Ardennes, guarding an invasion corridor from the Spanish Netherlands, so a Spanish army striking toward Paris had to be intercepted at this fortified border town.

Why then: By 1643 the rigid Spanish tercio squares had fallen behind newer flexible linear tactics and better-coordinated artillery, while Spain, exhausted by the Thirty Years' War and internal revolts, could no longer sustain the dominance it had held for over a century.

• The roughly 21-year-old French commander (later renowned as a great general) led the victory in 1643.
• It broke the legend of the Spanish tercios.
• The battle signaled Spain's decline as the leading European power.

Round 5

Withheld from the archive

This round was played, but we do not republish it here. Recent events involving mass civilian casualties are excluded from our public archive under our content policy, whatever their place in the day’s puzzle.