CREATE TABLE table_34971 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT)

Which First elected is the lowest one that has an Incumbent of william stewart?
SELECT MIN("First elected") FROM table_34971 WHERE "Incumbent" = 'william stewart'
SELECT MIN("First elected") FROM "table_34971" WHERE "Incumbent" = 'william stewart'