when did the institution at chapel hill, North carolina join acc?
CREATE TABLE table_28744929_1 (
    joined_acc VARCHAR,
    location VARCHAR
)
SELECT joined_acc FROM table_28744929_1 WHERE location = "Chapel Hill, North Carolina"
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: when did the institution at chapel hill, North carolina join acc? ### Input: CREATE TABLE table_28744929_1 (
    joined_acc VARCHAR,
    location VARCHAR
) ### Response: SELECT joined_acc FROM table_28744929_1 WHERE location = "Chapel Hill, North Carolina"