Solar eclipses in history: The Revolutionary War

1_Washington at the Battle of Monmouth.jpg

WASHINGTON (Sinclair Broadcast Group)- The story of the earliest eclipses observed in the United States would not be complete without Benjamin Franklin, statesman, scientist, humorist and astronomer.

European science and astronomy were booming in the 18th century with universities and scientific societies at the cutting edge of physics, natural sciences and astronomy. Founders like Franklin not only sought a place on the map for America as an independent nation, but also within the scientific world, contributing knowledge "to the Benefit of Mankind in general."

That mission was borne out in part with one of Franklin's earliest published work, Poor Richard's Almanack, an annual guidebook forecasting the major celestial happenings, including eclipses.

By 1743, Franklin founded the American Philosophical Society in Philadelphia to promote "useful knowledge" among the colonies. At the time America declared its independence, Franklin and his Society had helped cultivate America's earliest astronomers and statesmen (including future president of the Society, Thomas Jefferson), individuals who would go on to observe a series of stunning eclipses that took place during the Revolutionary War.


On the day of the eclipse, General George Washington was reportedly holding a war council in Hopewell, New Jersey. Prior to the eclipse, Washington had sent word to his commanders in the Continental Army, alerting them to coming phenomenon and preempting the fears and apprehensions of the soldiers.

George Rogers Clark, officer in the Virginia militia, reportedly used the eclipse to his advantage, telling his men that it was a good omen. Less than two weeks later on July 4, Clark and his men captured the city of Kasakia in one of the Revolution's westernmost campaigns.

For years after, the eclipse would be remembered as portending victory for the Continental Army in the Battle of Monmouth, which took place two days after the eclipse.

One week before the forecast date, British soldiers occupying Philadelphia left the city on news that the French had just entered the war.

The gradual obscurity of the sun, the decrease of her light, the sickly face of nature, and at last the total darkness which ensued, the stars appearing as at midnight, and the fouls seeking for their nightly shelter, caused a solemnity truly great."

This was good timing for David Rittenhouse, an astronomer, mathematician, mechanic and celebrated member of the American Philosophical Society living in Philadelphia.

According to records, Rittenhouse observed the eclipse along with Dr. William Smith, but records of their notes are scant.

Fellow member of the Philosophical Society and future President Thomas Jefferson was even closer to the direct pathway of the eclipse which traversed the mid-Atlantic and southern colonies. In a dispatch to Rittenhouse, Jefferson lamented, "we were much disappointed in Virginia generally on the day of the great eclipse, which proved to be cloudy."

Wartime conditions stressed the resources of the fledgling United States, which could account for the lack of observations.

One tremendous account has survived and was written in the North-Carolina Weekly Gazette on June 26.

The eclipse, which was visible on account of "tolerably clear" weather, "was observed with great attention, and some surprise to the ignorant," the paper reported.

"This was the greatest eclipse of the sun ever seen here by the oldest people now living among us, and exhibited a scene truly awful," the paper reported.

"The gradual obscurity of the sun, the decrease of her light, the sickly face of nature, and at last the total darkness which ensued, the stars appearing as at midnight, and the fouls seeking for their nightly shelter, caused a solemnity truly great."


Perhaps even more dramatic, were the conditions under which the second total solar eclipse of the Revolutionary War was observed.

Having missed the great scientific opportunity of the previous eclipse, scientists and statesmen in Massachusetts prepared to seize on the 1780 eclipse "to prove the new state of the new nation was capable of mounting a scientific expedition on its own initiative," wrote historian Robert Rothschild.

Harvard Professor Samuel Williams helped convene the team of scientists for the expedition to Penobscot Bay in Maine, a location Williams calculated as most ideal for observing the total solar eclipse.

Five years into the war, James Bowdoin, founder of the American Academy of Arts and Sciences, appealed to the Massachusetts legislature to outfit the group with supplies.

He wrote emphatically listing the causes for the mission: "That he cannot find that any total Eclipse of the sun has ever been seen here from the first Settlement of the Country, nor will any such be visible here until the year 1806; That the observations of Eclipses have been attended with so many advantages to mankind that they are universally esteemed object of Great Attention in every Civilized Nation."

Williams turned to the Board of War, which oversaw the entire Continental Army, requesting the use of a ship, the Lincoln galley, to bring the team to the observation site.

The petitions were granted and negotiations with the British forces were successful in guaranteeing safe passage for the expedition.

In a later account of the expedition, Wililams wrote, "Though involved in all the calamities and distresses of a severe war, the government discovered all the attention and readiness to promote the cause of science, which could have been expected in the most peaceable and prosperous times; and passed a resolve, directing the Board of War to fit out the Lincoln galley to convey me to Penobscot."

Ultimately, Williams' calculations were flawed. The location was off and he missed totality. However, what he observed was a phenomenon, Baily's Beads, that remained a scientific mystery until 1838.

Williams observed:

The sun’s limb became so small as to appear like a circular thread or rather like a very fine horn.
Both the ends lost their acuteness and seemed to break off in the form of small drops or stars some of which were round others of an oblong figure. They would separate for a small distance, some would appear to run together again and then diminish until the whole disappeared.

The expedition was a proof of concept of something that would become typical in the American experience, namely, institutions of science, government, academia and the military collaborating to further scientific and technological progress.


The annular solar eclipse of 1791 was exceptional for the man who forecast it, Benjamin Banneker, the country's first great African-American mathematician and astronomer.

Born outside of Baltimore to a biracial mother and a freed African slave father, Benjamin Banneker taught himself astronomy and advanced mathematics as a young man.

After the Revolutionary War, Banneker began recording his astronomical calculations and successfully calculated the April 14, 1791, eclipse, a date that contradicted the predictions of better-known mathematicians and astronomers of that day.

Beginning that same year, Banneker began publishing his own authoritative Almanack and Ephemeris, comparable in quality to Benjamin Franklin's almanac. Banneker sent a copy of his almanac to then-Secretary of State Thomas Jefferson who had openly professed his belief that African-Americans were intellectually inferior to whites.

To the author the Declaration of Independence and the words, "All men are created equal," Banneker penned a moving letter asking Jefferson to grant freedom to the slaves and provided a copy of his meticulous astronomical calculations.

I suppose that your knowledge of the situation of my brethren, is too extensive to need a recital here; neither shall I presume to prescribe methods by which they may be relieved, otherwise than by recommending to you and all others, to wean yourselves from those narrow prejudices which you have imbibed with respect to them, and as Job proposed to his friends, 'put your soul in their souls' stead;' thus shall your hearts be enlarged with kindness and benevolence towards them; and thus shall you need neither the direction of myself or others, in what manner to proceed herein.

Banneker included in his letter a reference to a bit of surveying work he was involved in during 1791 as a member of a surveying team commissioned by President George Washington to map the District of Columbia, the territory that would soon be the nation's capital.

close video ad
Unmutetoggle ad audio on off