On the corner of J and 2nd Streets, a man with a sheriff's star and gun holster slung around his waist cupped his hands and loudly announced, "Citizens of Sacramento! The mayor of Sacramento has an announcement!" If you were expecting Kevin Johnson to address the growing crowd of bystanders, you were sure to be disappointed. Saturday's Gold Rush Days hosted plenty of important Sacramentans, circa 1850. The free four-day event took over Old Sacramento with 200 tons of dirt and about 200 reenactors in 1850s-style garb. Attendees milled around the Embarcadero Tent City, a field of canvas tents that featured 1850 institutions such as a blacksmith, lace-maker, tinsmith, dentist, Mormon batta