The P-rade, one of the most popular and colorful reunion events, officially began in the late 1890s but evolved from earlier traditions.
Beginning in the 1860s, alumni formally processed to Commencement Day dinner meetings. In 1888, Princeton and Yale began scheduling one of their baseball games at Princeton on the Saturday before Commencement — and as this coincided with class dinners, alumni attendance was high and many classes formally marched to the game at University Field.
Then, in October 1896, when the newly renamed Princeton University celebrated its 150th anniversary, 2,800 undergraduates and alumni took part in a mile-long procession through the campus and town; most carried an orange torch or lantern, and many classes wore coordinated costumes. Inspired by the grandeur and organization of this parade, in 1897 all returning classes joined to march in order to the baseball game.
Gradually, classes began to distinguish themselves with ever-more elaborate costumes, signs and stunts. In 1913, graduating seniors started to wear "beer jackets" as their costumes, with a class logo emblazoned on the back. To this day, each graduating class designs its own class jacket, worn for the first time during Reunions weekend. Over time, P-rades and Reunions increasingly became a family affair, but it was not until the undergraduate body became coeducational in 1969 that women were officially welcome to participate in the P-rade.
Despite occasional route changes over the years, the procession order remains traditional. At 2 p.m. on Reunions Saturday, the Nassau Hall bell tolls and the 25th Reunion Class leads the P-rade from Nassau Hall to Poe Field. The classes then process in descending order, beginning with the "Old Guard" (classes beyond the 65th Reunion), followed by the 65th Reunion Class and each class prior, and ending with the graduating seniors. Graduate alumni march between the 24th and 26th Reunion Classes. The P-rade ends when the senior class sprints onto Poe Field, charging past the reviewing stand where the University president, the president of the Alumni Association and other dignitaries watch and wave.