September 16 in History

The United States National Hurricane Research Project dropped eight cylinders of silver iodide into the eyewall of Hurricane Esther on September 16, 1961, producing a measurable 10 percent reduction in wind speed and launching one of the most ambitious weather modification programs in American history. The experiment, conducted by aircraft that flew directly into the hurricane's eyewall at roughly 10,000 feet, was based on the hypothesis that seeding clouds with silver iodide would create additional ice crystals that would disrupt the storm's internal convection cycle and weaken it from the inside. The initial results seemed to confirm the theory, and the success led directly to the establishment of Project Stormfury, a joint initiative between the National Oceanic and Atmospheric Administration and the U.S. Navy that ran from 1962 to 1983. Stormfury conducted seeding experiments on several Atlantic hurricanes over the following two decades, producing ambiguous results that scientists debated intensely. The fundamental problem was distinguishing the effects of the seeding from natural fluctuations in hurricane intensity that occur regardless of human intervention. By the late 1970s, improved understanding of hurricane dynamics revealed that tropical cyclones contain far less supercooled water than the seeding hypothesis required, making it unlikely that silver iodide could produce meaningful changes in storm strength. Project Stormfury was quietly discontinued. The program remains a fascinating episode in the history of humanity's attempts to control weather, and the scientific data it generated contributed significantly to modern hurricane forecasting models.

Representatives from forty-six nations signed a treaty on September 16, 1987, that would repair a hole in the sky and become the most successful environmental agreement in human history. The Montreal Protocol on Substances that Deplete the Ozone Layer committed signatories to phasing out chlorofluorocarbons and other chemicals that were destroying the stratospheric ozone shield protecting life on Earth from ultraviolet radiation. Former UN Secretary-General Kofi Annan later called it "perhaps the single most successful international agreement to date." The crisis had been building since 1974, when chemists Mario Molina and F. Sherwood Rowland published a paper demonstrating that CFCs, widely used in refrigerators, aerosol cans, and industrial solvents, released chlorine atoms when they reached the stratosphere. Each chlorine atom could destroy tens of thousands of ozone molecules before being neutralized. The chemical industry dismissed the findings as speculative, and regulatory action stalled. Then, in 1985, British Antarctic Survey scientists reported a massive seasonal thinning of the ozone layer over Antarctica, so severe that their instruments initially rejected the readings as errors. The Antarctic ozone hole transformed the debate. Satellite data confirmed the findings and revealed the thinning was accelerating each year. Public alarm, combined with mounting scientific consensus, pushed governments to act with unusual speed. Negotiations in Montreal produced a protocol that initially called for a 50 percent reduction in CFC production by 1999, with subsequent amendments strengthening the targets to a complete phaseout. The protocol worked. Global CFC production dropped by over 99 percent, and the ozone layer has been slowly recovering since the early 2000s. Scientists project full restoration by approximately 2066 for the Antarctic hole. The agreement’s success rested on a combination of clear scientific evidence, viable chemical substitutes, a funding mechanism to help developing nations transition, and the willingness of industry to adapt once regulation became inevitable. Climate scientists have spent decades trying to replicate the Montreal model for greenhouse gas emissions, with far less success.

Father Miguel Hidalgo rang the church bell in the small town of Dolores before dawn on September 16, 1810, summoning his parishioners not for mass but for revolution. The speech he delivered that morning, known as the Grito de Dolores, called on the people of New Spain to rise against the Spanish colonial government and fight for their land, their liberty, and the Virgin of Guadalupe. The date became Mexico’s Independence Day, and Hidalgo’s cry is reenacted every year by the president from the balcony of the National Palace in Mexico City. Hidalgo was an unlikely revolutionary. A sixty-year-old Creole priest with a taste for French Enlightenment philosophy and a talent for winemaking, he had joined a conspiracy of disaffected Creole elites who resented their exclusion from power by peninsular-born Spaniards. The plotters had planned to launch their revolt in December, but the conspiracy was betrayed to colonial authorities in early September. Facing arrest, Hidalgo decided to act immediately. The movement he unleashed was far more radical and chaotic than the genteel political revolt the conspirators had envisioned. Hidalgo’s followers, drawn primarily from Indigenous and mestizo communities, swelled into an army of tens of thousands within weeks. They swept through the Bajio region, capturing Guanajuato in a bloody assault on the Alhondiga de Granaditas, a fortified granary where Spanish forces and Creole families had barricaded themselves. The massacre that followed alienated many of the Creole elite whose support the revolution needed. Hidalgo’s army marched to the outskirts of Mexico City but turned back without attacking, a decision that remains one of the great mysteries of Mexican history. Royalist forces regrouped, and by early 1811, Hidalgo was captured, defrocked by the Inquisition, and executed by firing squad. His head was displayed in an iron cage at the Alhondiga for ten years as a warning. Yet the movement he started could not be extinguished. Other leaders, notably Jose Maria Morelos and later Agustin de Iturbide, carried the fight forward until Mexico finally achieved independence in 1821. Hidalgo is remembered as the Father of Mexican Independence, and September 16 remains the country’s most celebrated national holiday.

Over 100,000 settlers lined up at the borders of the Cherokee Outlet in what is now northern Oklahoma on September 16, 1893, waiting for the signal to race in and claim land. At high noon, gunshots and bugle calls launched the largest and most chaotic land run in American history. Within hours, settlers had staked claims to approximately six million acres of what had been designated Cherokee territory. The Cherokee Outlet, often incorrectly called the Cherokee Strip, was a sixty-mile-wide band of land stretching westward from the 96th meridian. It had been assigned to the Cherokee Nation as part of the 1828 and 1835 treaties, intended as a western outlet to hunting grounds on the Great Plains. The Cherokee used the land primarily for grazing leases to Texas cattlemen, generating income for the tribe. The federal government purchased the Outlet from the Cherokee in 1891 for approximately $8.6 million, or about $1.40 per acre, under heavy political pressure from settlers who demanded the land be opened for homesteading. The price was well below market value. The land run itself was pandemonium. Participants arrived on horseback, in wagons, on bicycles, and on foot. Some traveled by specially arranged trains. "Sooners" entered the territory before the legal start time and hid until they could emerge and stake claims. The practice was so common that Oklahoma later adopted "Sooner State" as its official nickname, transforming a term for cheaters into a point of pride. Towns appeared overnight. Enid and Perry were established within hours, complete with provisional governments and property disputes. Violence broke out over contested claims. Federal marshals attempted to maintain order but were vastly outnumbered. The Cherokee Outlet land run was the last and largest of the Oklahoma land runs. It completed the transfer of Indian Territory to white settlement that had begun with the Land Run of 1889. The displacement of indigenous peoples from their legally guaranteed territories, accomplished through a combination of federal legislation, economic pressure, and raw demographic force, remains one of the defining injustices of American westward expansion.

A horse-drawn wagon packed with 100 pounds of dynamite and 500 pounds of cast-iron sash weights exploded at the corner of Wall and Broad Streets at 12:01 p.m. on September 16, 1920, just as lunchtime crowds poured out of the financial district’s banks and brokerage houses. The blast killed 38 people and wounded over 400, shredding bodies with shrapnel that gouged scars into the limestone facade of the J.P. Morgan building that remain visible more than a century later. The bombing was the deadliest act of terrorism in the United States until the Oklahoma City attack seventy-five years later. The wagon had been parked directly across the street from the Morgan bank’s headquarters, the symbolic and literal center of American capitalism. The timing, seconds after the noon bells of Trinity Church rang, ensured maximum casualties among office workers on their lunch break. The horse and wagon were obliterated, and the blast blew out windows for blocks in every direction. No one was ever convicted of the attack. The Bureau of Investigation, predecessor to the FBI, pursued leads for years, focusing primarily on Italian anarchist groups inspired by Luigi Galleani, the same movement responsible for a series of package bombs and the 1919 bombings that targeted Attorney General A. Mitchell Palmer’s home. The leading suspect, Mario Buda, an associate of Sacco and Vanzetti, reportedly fled to Italy shortly after the explosion. The case was officially closed in 1940 without charges. The bombing occurred during a period of intense social upheaval known as the First Red Scare. Labor strikes, anarchist bombings, and the recent Russian Revolution had created widespread fear of radical subversion. The Palmer Raids of 1919-1920 had rounded up thousands of suspected radicals for deportation. Wall Street reopened the next morning in a deliberate display of defiance, and the Morgan bank refused to repair the shrapnel damage to its facade, treating the scars as a monument to resilience. The attack is largely forgotten today, overshadowed by the terrorism of later eras, but it established a template for political violence aimed at financial centers that has been repeated throughout the decades since.