While Richmond VA is still the first electric transit system proved in 1888 by Frank J Sprague, apparently Montgomery Alabama was the city with the distinction of the first electric streetcar line in 1886. Or was it? The often unsung electrician was Charles Van Depoele and he opened 11 electric railway lines before Sprague opened his network in Richmond. The first being a demonstration line in Chicago in 1883. However these systems were prone to breakdowns and were often in need of fixing.
Another electrician, Leo Daft, had built electric lines on Pico in LA and in New Jersey, only to have issues with trollers coming off the wires and reliability. It wasn't until Frank J Sprague that systems were finally reliable enough and the invention of the spring loaded trolley pole (with the help of Van Depoele's first troller idea) kept the wire and trolley in constant contact. However Mr. Sprague recognized himself that the first regularly operating trolley line was Mr. Daft's in Hamden Line in Baltimore, constructed in 1885.
Mr. Sprague himself opened a line in St. Joseph Missouri in 1887 but proved himself when he electrified and ran 40 cars in Richmond VA in 1888. He also proved to investors that the vehicles would still work when they were backed up end to end, all pulling electricity from the same wire. He shouldn't get all the credit since there were many that came before him, but he's often credited with being the father of electric transit.
So which was the first? Are we going by reliability? By first operating date? By demonstration? I would say they all win since they all contributed to the cause. It's just unfortunate that they haven't gotten the recognition they deserve for their contributions.
H/T Streetsblog Cap Hill & Urban Mass Transit