Something was in the air. People on their daily rounds along the roads of Dorchester and Milton Village turned toward the Neponset River, inhaled the spring breeze, and took a deep whiff. The smell of chocolate was in the air.

The year was 1765. The heavenly scent drifted from a sawmill on the banks of the river within eyeshot of Boston. Inside the mill, an Irishman watched two giant millstones grinding fragrant cocoa and sounding a call to a culinary revolution that was to spread from Dorchester and conquer the collective palate of America.

In the fall of the year before, Dr. James Baker had smelled an opportunity for a mouth-watering, money-making product that had materialized in a chance meeting on a local road with a down-on-his-luck Irish immigrant named John Hannon.

Baker, a Harvard graduate who had practiced “physicke [sic],” medicine for a time, and had run a Dorchester store, learned from their encounter that even though the Irishman did not have a shilling in his pocket, he possessed a prized skill: He knew how to make chocolate, for which colonists were willing to part with steep sums even though after paying for the pricey product, imported from the West Indies, they still had to “work” for their “fix” by grinding the chocolate with mortar and pestle or by using cumbersome, expensive “hand mills.”

Most significantly for Baker, the Irishman not only knew how to make the “sweet stuff,” but he also could set up and run a chocolate mill. Several New Englanders had tried to set up chocolate-grinding operations, but none had taken off. The closest that any entrepreneurs had come was in Providence, in 1752, when Obadiah Brown had built a water-powered mill and had churned out four hundred pounds of the treat for Newport merchants. He was not, however, in the business for the long haul, just for a quick and lucrative profit.

Baker took on the challenge, betting his savings and his energy on Hannon’s expertise for a venture that he hoped would prove a long-term success.

Although the partners didn’t need a huge space to launch their scheme, they did require unlimited water power. And they did not need to look any farther than the Neponset after Baker bought a sawmill nestled alongside the river.

By spring 1765, Hannon was ready to put the plan to the test by grinding cocoa beans between two massive, circular millstones. Now, his partner would learn whether the Irishman knew his craft or else had had sold him a bill of goods.

Hannon set the top millstone to one-third, the speed used to grind corn. As the stone groaned and began to spin, he poured cocoa beans into a hole cut through the its center. Then, the Neponset’s flow set the bottom stone whirling, and the motion of both “wheels” pulverized the beans into a thick syrup. Then, he and Baker first poured the liquid into a giant iron kettle and then into molds, where the concoction cooled to form chocolate “cakes” that looked more like “bricks” in weight and consistency. With that first batch, Hannon proved that he could deliver the goods. America’s first bonafide chocolate factory had been born along Dorchester’s banks.

No one knows exactly how and where Hannon had honed his expertise with chocolate. His past was – and is – elusive. But the enigmatic Irishman’s and the Dorchester physician’s new process was poised to cure “chocolate-lovers’ elbow” - the soreness that colonists endured from grinding their own cocoa beans with their own pestles or hand mills.

Rising orders compelled Baker and Hannon to move the operation in 1768 to a larger space on the Neponset, with Baker renting a fulling [cloth] mill from his brother-in-law, Edward Preston. Preston, however, was not satisfied with merely being the chocolatiers’ landlord. He had his eyes on the business itself. For the moment, he appeared “interested” in only a curious fashion, but all that would change.

In 1772, Baker, with sales continuing to swell, opened a second Dorchester mill. Speculation that he and Hannon, who continued to operate the other plant, had quarreled and had either parted ways or forged a looser partnership, abounded. Baker had learned much from the Irishman: Nhe new mill turned out nearly nine hundred pounds of chocolate in 1773.

Baker’s decision to branch out proved both profitable and lucky, for in 1775, Hannon’s site burned to the ground. The Irishman, probably able to foot his own operating costs by that time, rented space in a Neponset snuff mill, grinding and pouring “cakes” once again and presumably making sure that no tobacco residue from the adjoining business drifted into his pouring kettles.

With the outbreak of the American Revolution in 1775, the Dorchester chocolate-makers struggled to stay in business. Their dependence upon cocoa from the West Indies forced them to smuggle shipments of beans through the web of Royal Navy warships prowling the Eastern seaboard.

Even after the Patriot cannons bristling atop Dorchester Heights helped force the “lobsterbacks’” departure from Boston, Baker and Hannon still faced the headache of running beans through the Royal Navy’s gauntlet, not to mention paying the war-inflated costs of cocoa.

In 1779, Hannon reportedly vanished on a voyage to buy beans in the West Indies. No one in Dorchester ever saw or heard from him again. Various sources believe he perished in a shipwreck; however, others contend that he vanished only from his vitriolic marriage to a Boston woman named Elizabeth Doe. But to Hannon’s partner, Dr. James Baker, business history beckoned.

He was soon enmeshed in legal wrangles with Hannon’s widow, who seemed intent on running her husband’s mill with his capable apprentice, Nathaniel Blake, as her workhorse. Blake, deciding that Mrs. Hannon was running the business into the ground, walked out on her and had little trouble in finding a new post – with James Baker.

By 1780, Baker had wrested his former partner’s mill from the widow, presumably by buying her out. By consolidating the operation under one roof on the site of the mill that had burned down in 1775, Baker saw his sales soar.

Watching the cash that chocolate-making poured into his brother-in-law’s account spurred Edward Preston to make a move after 12 years of seeing Baker struggle his way to success. He had studied the operation from millstones to handbills. In the 1790s, a Preston’s chocolate vied for space on tables and in cupboards with Baker’s product.

Some four decades later, James Baker, the Harvard doctor and businessman who had launched America’s first permanent and profitable chocolate factory, stepped down as “the king of cocoa.” He chose his son Edmund as the successor to the family business.

Edmund Baker soon began taking the venture to levels that his father and Hannon could scarcely have dreamed of. In 1806, Baker Chocolate’s new chief opened a state-of-the-art mill alongside the Neponset and started up a gristmill and a cloth mill nearby. With the Baker complex the focal point, the Neponset was dubbed “the river of American business.”

Baker expanded sales from the Northeast to the western outposts of the young republic’s widening borders; however, come 1812, America’s second war with Britain suddenly heaped upon Edmund Baker the same shipping problems his father had suffered during the Revolution. This time, the Royal Navy’s squadrons choked off cocoa shipments so effectively that the kettles and molds inside the Baker chocolate mill stood virtually empty for two years.

With the war’s end in 1814, cartloads of cocoa beans rumbled into the impressive, three-story stone edifice Baker had built. Soon, Baker’s best was on the shelves of America’s general stores again.

Edmund Baker later entrusted the company to his son Walter who moved to expand his work force. In a sign of the changing times, two of his were young women, Mary and Christiana Shields, who walked onto the plant floor in petticoats in 1834. By 1846, Baker’s payroll included several women.

Walter Baker’s mill, the fragrance of its chocolate to many passersby notwithstanding, was hardly a comfortable workplace. In summer, employees swooned from the kettles’ brown molten fumes and from the temperature within and outside the factory. In winter, gusts roared from the Atlantic and up the Neponset, the chill assailing workers inside and outside the plant and making the steaming kettles a desirable spot around which to gather.

The Baker workers nonetheless made their boss the first name in American chocolate, a success that attracted tough competition from chocolate-making interlopers. By 1835, the Preston mill was rolling out 750 pounds of the product a day. And by 1842, the banks of the Neponset featured a third chocolate competitor, Webb & Twombley. The scent of chocolate permeating the area led locals to call the site “Chocolate Village.”

The pressure to fill endless wagonloads of “brown gold” was acute for Baker and his Dorchester rivals alike, for, with refrigeration for chocolate products nonexistent, the millstones ground to a halt in summer. Finally, in 1868, the advent of refrigeration turned the Chocolate Wars into year-round combat.

Walter Baker died in 1852, before the family could reap refrigeration’s benefits to the business. His passing marked the end of the Bakers’ hegemony in the chocolate business, which they had ruled for nearly ninety years. The Baker Chocolate Factory continued to turn out its near-legendary products along the Neponset until 1965. In that year, two centuries after a Dorchester doctor/shopkeeper and an Irishman set their first two millstones into motion, General Foods, Baker’s parent outfit since 1927, shut down the venerable red-brick plant and moved the operation to Dover, Delaware.

Still, it is in the annals of Dorchester, not Dover or anywhere else, that the proud legacy of Baker Chocolate truly lives as the site of America’s first successful chocolate mill, where cocoa was turned into cash.

Today, America’s love affair with chocolate waxes unabated, testimony to the “taste” and acumen of Dr. Baker and an Irishman named John Hannon.