The portion of present-day MD 33 between Easton and Saint Michaels was designated one of the original state roads when the Maryland State Roads Commission laid out the original state road system in 1909. However, the Easton–Saint Michaels road was not considered a necessary component of the system, so construction in its modern form was delayed in favor of the Easton–Wye Mills road. A section of the road between the eastern intersection with MD 329 and MD 370 was paved by 1910. The first sections of modern MD 33 constructed by the State Roads Commission were between Saint Michaels and Claiborne, which became the terminus of the Claiborne–Annapolis Ferry in 1919. Sections were completed between the two villages in 1919 and 1920. A section of the highway was also completed between Easton and the MD 370 intersection in 1920. The Easton–Claiborne Road was completed in 1924. When numbers were assigned to certain state highways beginning in 1927, the road was designated MD 17.