William L. Mercereau (born June 9, 1866 – June 22, 1957) was an American design engineer and business manager of train ferries for the Pere Marquette Railway. He supervised their railroad-over-water system of steel train ferries which operated from Ludington, Michigan which was the largest carferry system in the world. Mercereau was involved in the implementation of loading a complete railroad car full of freight directly onto ships as one unit rather than transferring bulk material from railroad cars to steamship vessel holding tanks and back again at its final destination. Early life and education Mercereau was born at Union, New York, on June 9, 1866. As a boy of fourteen he worked part-time in a drug store in his hometown. When he was 18 in 1884 Mercereau went to Montana and Idaho, where he worked in drug stores as a general laborer. He later moved back east to Saginaw, Michigan, and as a young man of he started as a coal stoker on locomotives for the Flint and Pere Marquette Railroad. After just more than a year at this job he had increased his weight by . Mercereau then took on a job associated with bulk shipping of material in steamships which the railroad company operated out of Ludington, Michigan. He was a ship's clerk working out of the company's office at Bay City, Michigan. The first steamship he worked on was the break-bulk steamship Pere Marquette No. 2, that carried large quantities of salt in bulk. He later worked on the steamships Pere Marquette No. 3 and No. 5 for a few years. These vessels were handled by freight crews that took the material off railroad boxcars and transferred it into the bulk carrier vessel tanks to be shipped across Lake Michigan to Wisconsin. There another freight crew would unload the steamship vessel tanks and transfer back onto railroad cars. This was a costly, labor-intensive, time-consuming process for each break-bulk transfer that took away profits. Mercereau then quit working for the railroad company and went to college in St. Louis, Missouri, to obtain a business degree. After graduation he returned to Saginaw in 1897 and became an assistant manager in the railroad company's main office. In August 1898, he was promoted as assistant to the superintendent of marine operations at Ludington. After a few months on the job he took over the position of the previous superintendent. Career