gistfile1.cs

public static void CallAPI(ParamType param)
{
  var resetServicePoint = false;
  var origSecurityProtocol = System.Net.ServicePointManager.SecurityProtocol;
  try
  {
    System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Ssl3;
    resetServicePoint = true;
    // Make your API call here
  }
  finally
  {
    if (resetServicePoint)
    {
      try { System.Net.ServicePointManager.SecurityProtocol = origSecurityProtocol; }
      catch { }
    }
  }
}