Cant give you an exact date but from looking at 3 things..the red coat, the helmet and the long bayonet/scabbard gives me the idea that this is a lead solder depicting a soldier of the Kings Army..British soldier from later 1800's who you would see fighting in Africa, India etc.
If this is your very first find let me commend you on an excellent job. Plz do not clean it. Some if these lead soldiers can be valuable however since your little guy apparently took a cannon shot to his lower leg he will not bring much value except that its a heck of a find.