Culture File 18:
In North America, people may invite business acquaintances or co-workers to their homes. American houses are generally large and people like to entertain at home. It is seen as more personal than entertaining in a restaurant, it would be normal to take a gift if invited to someone’s home.
Flowers are always a safe gift. Others are chocolate or wine, but something typical from your country is best of all. It will be a friendly occasion, and you will eat with their partner, and possibly their children. Once you have met the family of a business acquaintance, it is polite to ask about them at subsequent meetings.