MY GREAT-GRANDFATHER, Arthur Manvel Dailey, arriving in Seattle in 1888, soon found work in the coal mines northeast of Renton. His sweetie (my future great-grandmother, Agnes Johnson) was a schoolteacher in distant Ballard. Family lore tells of the arduous round-trip from Newcastle to Ballard each Sunday, but for an ardent young suitor, a few hours of travel was fair exchange for the weekly allotment of kisses.

And yet, were it not for a 40-mile stretch of “small, grimy, seemingly insignificant” pioneer railway, asserts historian Kurt E. Armbruster in his colorful latest book, “Pacific Coast: Seattle’s Own Railroad,” my ancestors’ romance — not to mention a growing young city’s fortunes — might have been much dampened.

From their arrival in 1851, early settlers knew that hopes for a profitable future rode an iron horse. Arthur Denny said he located on Puget Sound believing “that a railroad would be built across the continent to some point on the northern coast within … 15 or 20 years.”

Over the next two decades, however, those expectations were dashed by a number of obstacles, including conflict with native peoples, slumps of the economy and the U.S. Civil War. In 1873 came more bad news. To Seattle’s dismay, the Northern Pacific Railroad sited the terminus of its cross-country line in Tacoma, leaving the Queen City isolated on her Elliott Bay throne.

But as railroads languished in King County, another economic engine built up steam. Immense seams of coal, pushed up by the Seattle Fault, had been discovered by the mid-1850s, and the foothills east of Lake Washington soon became teeming hives of activity. “In the 19th century,” says Armbruster, “coal was king … and Seattle had coal” — indeed, one of the largest coalfields on the West Coast.

Vast shipments of “black gold” were readily snapped up by energy-hungry San Francisco to support its industry and transportation. But the convoluted, herculean transport from coalface to waiting sailing ships in Elliott Bay took long days and cut deeply into profits.

Seattle’s citizens, stung by the rebuff of big rail, conjured an ingenious solution: Build a railway that incidentally provided King Coal with a profitable route to market. And on May 1, 1874, thousands of eager Seattleites assembled to do just that. On that single day, a mile-long stretch of rail bed was cleared along the base of Beacon Hill for the somewhat presumptuously named Seattle & Walla Walla Railway, eventually renamed the Pacific Coast Railway.

In the end? Rails that, although never extending much farther east than Black Diamond, shortened the mine-to-dock transport from days to mere hours. As a result, Seattle — and Grandpa Dailey — realized benefits that endured for decades to come.