William Fadjo Cravens is the only candidate who was first elected in 1939.
CREATE TABLE table_18630 (
    "District" text,
    "Incumbent" text,
    "Party" text,
    "First elected" real,
    "Result" text,
    "Candidates" text
)
SELECT COUNT("First elected") FROM table_18630 WHERE "Incumbent" = 'William Fadjo Cravens'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: William Fadjo Cravens is the only candidate who was first elected in 1939. ### Input: CREATE TABLE table_18630 (
    "District" text,
    "Incumbent" text,
    "Party" text,
    "First elected" real,
    "Result" text,
    "Candidates" text
) ### Response: SELECT COUNT("First elected") FROM table_18630 WHERE "Incumbent" = 'William Fadjo Cravens'