What railroad for which Oakes Ames is credit as being the single most important influence in building was caught up in the  Crédit Mobilier scandal?
Crédit Mobilier of America scandal The Crédit Mobilier scandal of 1867, which came to public attention in 1872, involved the Union Pacific Rail Road and the Crédit Mobilier of America construction company in the building of the eastern portion of the First Transcontinental Railroad. The scandal was in two parts. The construction company charged the railroad far higher rates than usual, and cash and $9 million in discounted stock were given as bribes to 15 powerful Washington politicians, including the Vice-President, the Secretary of the Treasury, four senators, and the Speaker and other members of the House.
Grantism Grantism became a byword for political incompetence, corruption and fraud during the 1870s, while Ulysses S. Grant was President of the United States. The 1869–1877 presidency of Ulysses S. Grant was marred by many scandals and fraudulent activities associated with persons within his administration, including his cabinet, that was in continual transition, divided by the forces of political corruption and reform. Among them were: Black Friday, corruption in the Department of the Interior, the Sanborn incident, and the Whiskey Ring. (The Crédit Mobilier scandal, although exposed during his tenure, is not considered a Grant scandal.)