How did Lord Dinwiddie react when the French rejected George Washington's demands at Fort Le Boeuf?

In January 1754, even before learning of the French refusal to decamp, Dinwiddie sent a small force of Virginia militia to build a fort at the forks of the Ohio River, where the Allegheny and Monongahela rivers merge to form the Ohio (present-day Pittsburgh). The French quickly drove off the Virginians and built a larger fort on the site, calling it Fort Duquesne, in honour of the Marquis de Duquesne, the then-governor of New France.