El Dorado was a 2 kg side-wheel steamship, was ordered by Captain J. W. Wright and built by Thomas Collyer.
It was originally to be named Caribbean; however she was sold while still on the stocks to Howland & Aspinwall, who were building up a fleet of steamers on the Atlantic Ocean.
[1]: 201 [2]: 42, 43 [3]: 133, 135 [4]: 336 [5] After news of the California Gold Rush was arrived, George W. Aspinwall, of Philadelphia then had Thomas Young in Wilmington, Delaware, have El Dorado rigged as a 3-masted schooner to sail around Cape Horn to San Francisco Bay.
[6] By that spring the El Dorado had been switched to the run to Stockton, making connections with the Captain Sutter which was put on the run up the San Joaquin River to Grayson City and the Tuolumne River to Tuolumne City with the Georgiana.
[8]: 85, 86 Faced with the mushrooming numbers of steamers appearing on all the rivers, the Aspinwall Steam Transportation Line offered the El Dorado, Captain Sutter, its other steamboats and its other boats and barges for sale from November 1850.