CREATE TABLE table_59231 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Results" TEXT)

What is the lowest First Elected, when District is 'Massachusetts 10'?
SELECT MIN("First elected") FROM table_59231 WHERE "District" = 'massachusetts 10'
SELECT MIN("First elected") FROM "table_59231" WHERE "District" = 'massachusetts 10'