The town and community known as Connell, Washington had its beginnings when the Northern Pacific Railroad extended its line through what later became the town site. The railroad was built in stages, first from St. Paul, Minnesota, westward, and then also eastward from Ainsworth, located on the Snake River below Pasco.

The stretch of railroad from Ainsworth to Spokane was completed in 1880 and extended through what later became Connell. The Northern Pacific Railroad was controlled by Henry Villard, one of the great pioneers of western railroading. Villard also controlled the Oregon Railroad and Navigation Company, which built a railroad along the south shore of the Columbia River eastward from Portland as far a Wallula, where it connected with a branch line to Walla Walla.

In the late 1870s, Villard's western railroad had not yet become a part of the Union Pacific System and had no connection to the eastern United States. Through a successful financial deal, Villard managed to acquire control of the larger Northern Pacific Railroad. He planned to connect his O. R. & N. with the Northern Pacific and thus begin the first transcontinental railroad service to the Northwest.

Villard set about building the railroad eastward from Ainsworth, on the north bank, while at the same time, he was building a railroad from Wallula to the south side of the Snake River. He realized his dream on September 8, 1883, when the last spike of the completed line was driven at a ceremony at Gold Creek, Montana, some 58 miles west of Helena. Soon after, the first transcontinental passenger and freight trains passed through Connell. These first trains were ferried across the Snake River at Ainsworth, after which they went on to Wallula, where they connected with the O. R. & N. on their way to Portland. From there, they traveled by way of Kalama to Tacoma.

In 1884, the bridge across the Snake River was completed; however, it was not until 1887 that the main line across the Cascades to Tacoma and Seattle was completed. The town of Pasco then came into prominence, and Ainsworth gradually faded.

While at work building their transcontinental railroad, the Northern Pacific management decided to tap the rich Palouse country which, until then, was not served by any railroad. They started by building a branch line, beginning at what is now Connell, then called Palouse Junction. The branch line ran from the junction to Colfax, and was later extended to Moscow, Idaho. This line was known as the Columbia and Palouse Railroad, but it was owned and controlled by Northern Pacific. Construction of this branch, according to newspaper reports from the period, began early in 1882.

A correspondent of the Waitsburg Times, writing from Palouse Junction, described the area as “a waterless, sandy region, fit only for the abode of rattlesnakes and coyotes. At present there is a camp of railroad men here employed in grading. Considerable work was required in the immediate vicinity. The company is grading a Y here which requires considerable fills, while beyond is a cut over 1300 ft. long by 2 or 3 to 9 feet deep.”

Construction of the branch line into the Palouse region determined the location of a station at Palouse Junction. Otherwise, the railroad seems to have located stations near water. At the time that the branch line was built, there was no water in what later became Connell. It appears that the railroad depended on dug wells or springs rather than on the drilled wells which later became prevalent.

In 1883, soon after the first transcontinental trains passed through Palouse Junction, the railroad gave notice that the branch line was open as far as Endicott and Colfax. Villard successfully completed the railroad from St. Paul, Minnesota to Ainsworth, Washington and Palouse Junction became a point of some importance because it served as a connection to the rapidly developing Palouse country. The Pacific Northwest was indebted to Mr. Villard for his enterprise.

In the meantime, the O. R. & N. became a part of the Union Pacific system by extending its line eastward over the Blue Mountains to connect with the Oregon Short Line and the main line of the Union Pacific. In this financial shake-up, the Union Pacific also took over the Palouse branch of the Northern Pacific. Although this branch no longer belonged to the Northern Pacific, but instead to the Union Pacific, the connection at Palouse Junction continued to be used until the O. R. & N. extended its own line from the Palouse to Spokane. So, at least until 1889, Palouse Junction remained the only railroad gateway to the Palouse region.