CREATE TABLE table_28875 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" TEXT, "Result" TEXT, "Candidates" TEXT)

How many district has a candidate that was first elected on 1811?
SELECT COUNT("District") FROM table_28875 WHERE "First elected" = '1811'
SELECT COUNT("District") FROM "table_28875" WHERE "First elected" = '1811'