In reality, the first railroad through the region which came to be the Benning Yard was the Baltimore & Potomac RR, a surrogate of the Pennsylvania Railroad. They came thru this area as part of their "break the B&O's Maryland to DC monopoly" in the early 1870's, 1871 or perhaps early 1872 and they proceeded to croos the East Branch (today's Anacostia River) on a trestle, along a right-of-way similar but not exactly what we see today until approaching 6th Street SW when the line turned north along or near 6th Street until they crossed the Mall to where a depot was eventually constructed near where the 1941 National Gallery of Art Bldg. is located.
However, back to the Benning's area, this became a yard for them for many years, one of many in the DC region.
About a year later, the Baltimore & Ohio Railroad built a totally different line from their tracks which are located several miles west of the original Baltimore & Potomac line.
This line came (and still does) from Hyattsville thru the Benning's area down to a place, now long-forgotten called Shepherd's landing, some 12.5 miles from Hyattsville. While a totally separate corporation, it had the fancy name of "The Washington City & Point Lookout RR" and from its op[ening in March 1874 until November 1906, floated freight and passenger cars across the Potomac River from Shepherd's Landing to the Wilke's Street Wharf in Alexandria.
Both the B&O and the Pennsylvania RR had Benning yards and exactly which one did what and with whom, I do not totally know today but suffice it to say the B&O and the PRR were NOT on the friendliest of terms and had minimal; interchange for many years. Thankfully, that all changed over time, especially after the B&O's receivership of 1896-1899 when they were financially weakened to such an extent that the Pennsy actually had control of them, although they were forced to divest under ICC regs some years later, but the spirit of "friendship" and collegiality was sort of encouraged and they got along better after that and were made a major partner in the Potomac Rail yards as well as Washington's union station which was opened in late 1907, combining the 2 RR's separate depots located about a mile apart without connecting tracks in between.
As for the old Washington City & Point Lookout RR, it became known as the Alexandria Branch and during WW II, the Government built an emergency bridge across the Potomac River between the old Shepherd's Landin and near the Alexandria Power Plant and it was used by the B&O as an extra by-pass for the extra busy days of freight and troop movements during WW 2. After the War, it was offerred to the B&O which declined and it was removed in 1946 or 1947 and the Alexandria Branch settled into the sleepy little backwater line it amost always had been.
Over the next 20-30 or so years, the few remaining customers along the line slowly slipped away, all except the one at the end of the line just past the Naval Research Laboratory; Blue Plains treatment plant. After 9-11, the wisdom of shipping tankcar loads of the highly toxic chlorine along this line where thousands of people travel daily came into play and substitute methods of shipment or newer, less-toxic chemicals were substituted and the last 5-6 miles of the line, past bennings were finally abandoned.
Compiled by Robert Cohen