• 1862 - Passage of Morrill's Land Grant Act.  Signed by Pres. Lincoln, the act changed higher education by bringing agricultural and vocational studies to the mostly rural population of the U.S.
• 1870 - University established as the Ohio Agricultural and Mechanical College.
• 1878 - College renamed The Ohio State University.  The name change reflected a new emphasis towards the liberal arts, which alienated the agricultural community.
• 1882 - The Ohio Agricultural Experiment Station was established on the Columbus campus in 1882 with renewed focus on agriculture.
• 1887 - The Hatch Act established US agricultural experiment stations with research as primary mission.
• 1890 - A second Morrill Act added historically black colleges and universities to the land grant system.
• 1894 - The OAES was moved to Wooster in 1894, where it stands today as the Ohio Agricultural Research and Development Center (OARDC).
• 1880s - Plant Pathology first incorporated into courses offered by the Department of Horticulture and Botany.
• 1891 - The first plant pathology course  was taught by W. A. Kellerman, noted mycologist and plant pathologist who chaired the department from 1891-1908.
• Early 1900s - Extension programs were established to provide information to agriculture community and address horticultural, soil and disease problems.  Railway trains with educational displays traveled throughout southeast Ohio.
• 1902 - A.D. Selby was Ohio's first experiment station plant pathologist. He was botanist and chief of the new Department of Plant Physiology and Pathology from 1902 - 1923.  Selby was a founder and charter member of the American Phytopathological Society, and served as its third president.  The Department of Plant Pathology in Wooster is now housed in Selby Hall, named in honor of A.D. Selby.
• 1914 - Smith-Lever Act established the Cooperative Extension Service to establish outreach and education programs.
• 1948 - Leo L. Rummell was named both dean of the College of Agriculture at The Ohio State University and director of the Ohio Agricultural Experiment Station at Wooster.  Common departments in Columbus and Wooster were merged to form the Department of Botany and Plant Pathology.
• 1960 - Roy M. Kottman became dean and director of the Ohio Agricultural Experiment Station.  Kottman would later be named director of Extension, thus becoming the first person at Ohio State to administer all three branches - Research, Teaching and Extension.
• 1963 - Plant Disease Clinic established by Extensioin plant pathologists.  The clinic expanded to become the multidisciplinary Plant and Pest Diagnostic Clinic in 1985, and in 1996, was named the C. Wayne Ellett Plant Pest and Diagnostic Clinic in honor of Ellett for his many contributions as clinic director and plant pathologist.
• 1967 - Plant Pathology was established as its own Department.  Most of the botany faculty became part of a newly formed College of Biological Sciences.
• 1968 - Ira W. Deep served as the first chair of the Department of Plant Pathology from 1968-1984.  Deep chaired the committee that designed the Plant Protection undergraduate major, a multidisciplinary program that included programs in plant pathology, agronomy, entomology and horticulture.
• 1971 - Selby Hall was completed on the OARDC campus in Wooster to house the Department of Plant Pathology and microscopy facilities (now the Molecular and Cellular Imaging Center).
• 1981 - On the Columbus campus, the Department moved from the Botany and Zoology Building (now Jennings Hall) to the newly constructed Kottman Hall in 1981, where it resides today.
• 1982 - OARDC becomes part of The Ohio State University.  Since then the department has operated as a single academic department housed on two campuses.
• 1984 - Charles R. Curtis served as Professor and Chair of the Department of Plant Pathology from 1984-1996.  Curtis retired in 2007.
• 1996-2006 - Randall C. Rowe served as Department Chair.  After his retirement in 2006, Laurence V. Madden served as interim chair.
• 2007 - Michael J. Boehm was appointed Professor and Department Chair.
• 2008 - The Department of Plant Pathology is recognized internationally for its strength in Research, Teaching and Extension. 

Sources: A History of the Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center, by Lansing E. Williams and C. Wayne Ellett; A Brief History of OARDC: http://www.oardc.ohio-state.edu/history.asp.