1900-1909
1900
- McClure Hall. Architect: Rolph H. Miller.
- The first fraternity, Sigma Nu, was established. Fraternities and sororities, as well as boarding houses, offered housing alternatives, and often social opportunities, that UO lacked.
- The Associated University of Oregon Students (ASUO) was organized.
- Student newspaper was called the Oregon Weekly; microfilm copy is available in Knight Library.
1901
- Mechanical Hall. Architect: Edgar Lazarus.
1902
- Prince Lucien Campbell began his 23 years as UO's 4th president. First yearbook, the Webfoot, published.
1903
- First manned air flight, by Wright Brothers, at Kitty Hawk, N. C.
1904
- Kappa Sigma Fraternity built a house on the Millrace at 11th and Alder. First sorority (later Kappa Alpha Theta) organized.
- University Day. Conceived by UO President Prince Lucien Campbell as a constructive way to channel student energies as opposed to playing 'king of the mountain' on top of Villard Hall. Building sidewalks (replacing wooden planks) was an early University Day activity, and portions of sidewalks with 'University Day' and dates can be seen on the sidewalks leading to University Hall's west facade.
- Eugene's first automobile appears in 1904.
1905
1906
- "Carson's Lake" opens.
- The Library (Fenton Hall). Architect: Yousta D. Hensill.
- A major earthquake struck San Francisco and large portions of the West on April 18, 1906.
1908
- The first "O" was sited on Skinner's Butte. Re-painting the "O" became a routine event for Junior Weekend and University Day.
1909
- Mary Spiller Hall. Architect: Yousta D. Hensill.
- Men's Gymnasium. Architect: John Hunzicker.
- Engineering Hall. Architect: Percy Adams.