James Victor Uspensky (1883–1947) was a mathematician who wrote Theory of Equations. He graduated from the University of St. Petersburg in 1906 and received his doctorate from the University of St. Petersburg in 1910. He was a member of the Russian Academy of Sciences from 1921.
Uspensky joined the faculty of Stanford University in 1929-30 and 1930-31 as acting professor of mathematics. He was professor of mathematics at Stanford from 1931 until his death.
Uspensky is the one who kept alive Vincent's theorem of 1834 and 1836, carrying the torch (so to speak) from Serret; for more details see the article on Budan's theorem. For more details on Uspensky's life (in Russian) see the article in http://www.apmath.spbu.ru/ru/misc/uspenskii.html.