Problem loading a table with SQL data in c #

I'm creating a web page and I want to show a table with saved data from that same table on a SQL server. For now I have this:

public partial class historyTable : System.Web.UI.Page
    {
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    private void btnCargar_Click(object sender, EventArgs e)
    {
        System.Data.SqlClient.SqlConnection cn = new System.Data.SqlClient.SqlConnection("server=NameServer;uid=team;" +
          "pwd=contraseña;database=BaseDeDatos; Initial Catalog=history;Integrated Security=true;");

        cn.Open();
        System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand("SELECT * FROM history", cn);
        System.Data.SqlClient.SqlDataAdapter da = new System.Data.SqlClient.SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        dataGridView1.DataSource = dt;
        cn.Close();
    }
}

I'm trying to show the data in the "history" table but it says that I have a bug in dataGridView1.DataSource = dt; and dn cn.Close ()

Thank you.