Today is the 250th anniversary of the first day of the 3,059-day war that birthed the modern world. Commemorating the April 19, 1775, skirmishes at Lexington Green and Concord Bridge begins a celebration that will culminate July 4, 2026. These almost 15 months will inflame the perpetual scolds who, examining this nation’s history with a disapproving squint, see little to celebrate.

In the half-century since the bicentennial, however, many Americans have developed a deeper, sturdier patriotism. They have benefited from historians who demonstrate how mature minds can combine unblinking assessments of history’s inevitable mistakes, cruelties, tragedies and sorrows with gratitude for those who persevered, and reverence for what they achieved: a wonderful nation.

One such historian, Rick Atkinson, has now fired a shot heard ‘round the world where scrupulously clear-eyed but respectful American histories are savored. In 2019, he published “The British Are Coming,” which ended with the Jan. 3, 1777, Battle of Princeton. The final volume of his Revolution Trilogy will perhaps coincide with the 250th anniversary of the Oct. 19, 1781, world-turned-upside-down British surrender at Yorktown.

This year’s volume, “The Fate of the Day,” which ends in 1780 at Charleston, recounts the two stages of the battle of Saratoga (Sept. 19 and Oct. 7, 1777), arguably this nation’s most important military triumph. Victories at Gettysburg and Midway hastened the probable defeat of grave threats to the nation. Saratoga, by bringing France into the war on America’s side, assured the nation’s survival beyond infancy.

In 1925, Winston Churchill said, “In no field of man’s activity is the tendency of mass effects and the suppression of the individual more evident than in modern war.” As foreshadowed by 19th century Napoleonic Wars, when the battles of Austerlitz (1805) and Borodino (1812) involved 158,000 and 250,000 troops, respectively.

The Revolutionary War was premodern: At Saratoga, about 22,200 clashed, producing fewer than 1,500 dead and wounded. The war, far from being a collision of vast forces, was a theater of human agency — of unsuppressed individuals making choices based on principles. Of the roughly 200,000 who served in the patriot forces, only half were in Washington’s Continental Army, the rest in militias. Washington was not at Saratoga.

Desertions were almost ruinous. Washington worried that “we shall be obliged to detach one-half of the army to bring back the other.” This was partly due to American individualism. Washington: “A people unused to restraint must be led, they will not be drove.”

Eighteenth-century Americans, lacking social media, Netflix and other distractions, wrote letters and diaries in profusion, a staggering number of which Atkinson has read. Including those of Connecticut’s Moses Dunbar.

Dunbar wrote that he was “the second of sixteen children, all born to my Father by one wife.” Dunbar himself had five children with his first wife, and seven more with his second, Phebe.

His fervent Anglicanism caused him to align with the British, for whom he recruited support. He was convicted of high treason against Connecticut. In March 1777, Phebe, pregnant with his eighth child, was forced to ride with him in a tumbrel to the gallows. Dunbar’s father, a supporter of independence, reportedly offered to supply the hemp for the hanging.

What Americans call the Civil War (1861-1865) was actually our second such. More New Yorkers fought for than against the British. Atkinson says almost 20 percent of the population (excluding enslaved people) was loyal to Britain; 30,000 of them fought for it. Each side often treated the other savagely.

But, then, those who lived in the 18th century were inured to death, violent and otherwise, burying children swept away by disease and women who died during childbirth. “Typhus and other diseases,” Atkinson writes, “killed at least 8 percent of all passengers on transatlantic crossings.” Medicine was almost nonexistent, and where practiced was often more lethal than battle. Combat was often up close and personal, with edged weapons: swords, knives, hatchets and especially bayonets.

Eighteenth-century America, of which we are a reverberation, was both the age of reason and of barbarities. History, Atkinson reminds us, is always, as now, a compound of the elevating and appalling.

Americans who fear a rancorous plod toward America’s 250th birthday should remember: 250 years ago, the nation knew much worse. Then it healed, passed through the furnace of another civil war, then resumed its zigzag but upward path toward a more perfect union. Atkinson’s reminder is that the birth of this nation, like that of a baby, was painful but worth it.

George F. Will writes a twice-weekly column on politics and domestic and foreign affairs for The Washington Post.