Issued at the national convention of the American First Day Cover Society in Arlington, Virginia, on August 19, 1983, the 1-cent Omnibus was the lowest value of the Transportation Coil Series. The stamp depicts a horse-drawn omnibus, the urban mass transit vehicle of the 1880s. Intended as a change-maker for use in vending machines, it paid no particular postage rate.
The Bureau of Engraving and Printing printed the Omnibus on the Cottrell press, which used two curved plates to form the printing cylinder, leaving a crack between the plates. The plate number was placed beneath the last stamp to the right in each row. When ink flowed into the crack between the plates, a vertical line was printed immediately to the right of stamp with the plate number. The Bureau used six plates for the issued stamp. Alternating plate numbers appear every twenty-four stamps. Plate number 1 was paired with 2; plate 3 with 4; and plate 5 with 6. Only plate numbers 1 and 2 appear on first day covers. There were 790 million of the 1-cent Omnibus released in coils of five hundred and three thousand, all with overall tagging. There were 109,463 first day covers.