Simplify the following text for a Grade 8 native English-speaking person.
Original: On August 13 Schuyler dispatched him with a force of 900 to relieve the siege of Fort Stanwix , where he succeeded in the use of a ruse to lift the siege .
Simplified: On 13 August Schuyler dispatched him with a force of 900 to relieve the siege of Fort Stanwix , where he used a trick to end the siege .