Washington A. Roebling II arranged with William Walter, to take over his automobile company and use a vacant brewery in Hamilton, New Jersey, owned by the Kuser family.

The Mercer was available as a speedster, toy tonneau or touring car and were powered by four-cylinder L-head Beaver engines.

The T-head Raceabout was announced late in 1910 for the 1911 model year, this car was the idea of Washington A. Roebling II, and built by the engineer, Finley Robertson Porter.

[1] For 1923 an overhead valve six-cylinder (Rochester engine) was introduced with a three-speed Brown & Lipe gearbox.

The Raceabout's inline 4-cylinder T-head engine displaced 293 cubic inches (4,800 cc) and developed 55 horsepower (41 kW) at 1,650 revolutions per minute.

The Raceabout became one of the premier racing cars of the era- highly coveted for its quality construction and exceptional handling.

[4] In February 1914, Eddie Pullen, who worked at the factory from 1910, won the American Grand Prize held at Santa Monica, California, by racing for 403 mi (649 km) in a Raceabout.

For winning the 300-mile (480 km) big car event, Pullen won $4,000 and an additional $2,000 for setting a new world road race record.

Spencer Wishart, a champion racer who always wore shirt and tie under his overalls, was killed along with the car's mechanic, John Jenter.

[1] Production, which had ceased in 1924, was resumed late in the year and continued, though cars were mostly built from parts on hand.

Wahl contracted with Elcar Motor Company and its engineer Mike Graffis to build new Mercer prototypes.