Detailed Instructions: In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Problem:Passage: Following the war, Walker served on the editorial staff of the Springfield Republican before using his family and military connections to gain appointment as the Chief of the Bureau of Statistics from 1869 to 1870 and Superintendent of the 1870 census where he published an award-winning Statistical Atlas visualizing the data for the first time. He joined Yale University's Sheffield Scientific School as a professor of political economy in 1872 and rose to international prominence serving as a chief member of the 1876 Philadelphia Exposition, American representative to the 1878 International Monetary Conference, President of the American Statistical Association in 1882, and inaugural President of the American Economic Association in 1886, and vice president of the National Academy of Sciences in 1890. Walker also led the 1880 census which resulted in a twenty-two volume census, cementing Walker's reputation as the nation's preeminent statistician.
Link Information: The Centennial Commission turned to third-place winner's architect Henry Pettit and engineer Joseph M. Wilson for design and construction of the Main Exhibition Building. A temporary structure, the Main Building was the largest building in the world by area, enclosing 21.5 acre. Question: What building was the 1876 Philadelphia Exposition held at?
Solution:
Answer: the Main Exhibition Building