By 1855, Norton was one of the most respected businessmen in San Francisco, having rebounded from the fire of 1853 and profitably diversified his operations. Already his friends were referring to him as "Emperor." It was at this time that he hit on the bold idea of attempting to corner San Francisco's rice market--the city's large immigrant Chinese population providing a captive and hungry market, at a time when the only way rice (or almost anything else) arrived was aboard cargo steamships. Investors were quick to sign on, and in a matter of days Norton owned, practically speaking, all the rice in San Francisco. For the first few days it looked like yet another daring success for the Emperor, when two ships, well ahead of schedule and brimming with rice, steamed lazily through the Golden Gate. One shipment he might have been able to buy up as well; two was a backbreaker, and in a matter of minutes Norton was ruined.

He spent the next three years in court, and emerged penniless in 1858. Packing together his meager belongings, Norton disappeared for about nine months; no record tells where he went. He returned suddenly in the late summer of 1859, proudly walking the streets in a beaver hat and naval regalia, arguably mad. By September, Emperor Norton was no longer able to contain his secret. He walked into the offices of the San Francisco Bulletin and presented them with this single sentence, which they ran on the next edition's front page:

At the peremptory request of a large majority of the citizens of these United States, I, Joshua Norton, formerly of Algoa Bay, Cape of Good Hope, and now for the past nine years and ten months of San Francisco, California, declare and proclaim myself Emperor of these U. S., and in virtue of the authority thereby in me vested do hereby order and direct the representatives of the different States of the Union to assemble in Musical Hall of this city, on the 1st day of February next, then and there to make such alterations in the existing laws of the Union as may ameliorate the evils under which the country is laboring, and thereby cause confidence to exist, both at home and abroad, in our stability and integrity.
Norton I
Emperor of the United States
September 17, 1859

That day people on the streets began greeting Norton with deep bows and curtsies. The tacit public acceptance was immediate and profound, and San Francisco had a wise and caring monarch to reign over its gilded age.

Norton I ruled by proclamation, and it didn't seem to faze him if not all his edicts were carried out. If taxes or water rates were too high, he commanded that they be lowered; if there were inadequacies in city services, he ordered improvements. On the eve of the Civil War he temporarily dissolved the Union, and after the Prussian victory in 1872, he ordered a week of continuous celebration and thanksgiving. Bay Area newspapers competed for the honor of posting his proclamations, and more than once they devised fakes to generate sales and interest, a practice against which the Emperor railed angrily.

Few monarchs ever had Norton's common touch; he abjured seclusion and luxury. He attended every public function or meeting, always arriving by foot or bicycle rather than coach, and performed daily rounds of his capital's streets, making sure the police were on their beats, and that cleanliness, harmony and order prevailed. If he noticed someone performing some kind act or other, he might spontaneously ennoble them, from which practice the expression "Queen for a day" was obtained. The titles were especially popular with children, who would follow him in groups, looking everywhere for litter to pick up or old ladies to help across the street.

Norton's personal expenses were few. He ate free of charge at whatever restaurant suited him, had three seats reserved for him at every theatrical performance (one for himself and one each for his famously well-behaved dogs, Bummer and Lazarus); the city itself actually paid for his uniforms and the local Masonic Lodge paid for his small apartment. Nonetheless, whenever necessary, Norton had his own currency printed, which was accepted everywhere without question--at at time when U. S. paper money was still regarded with distrust in California. He also had the option of levying taxes, for which his normal procedure was to walk into the offices of an old business friend and politely announce an imperial assessment of ten million or so dollars, but could quickly be talked down to two or three, or perhaps a cigar, with which he would walk out entirely satisfied.

Still though, this isn't really legal, and feelings towards Norton I amongst the police were rather mixed. In January of 1867, in fact, he was arrested by an overzealous policeman "to be confined for treatment of a mental disorder," and held at the police station pending a hearing. The public outrage was immediate; every newspaper editorial denounced the action, and there was the real possibility of a riot. Chief of Police Patrick Crowley himself opened the cell doors, and issued a lengthy public apology to the Emperor. Norton was magnanimous about the whole affair, and from then on his relations with the police became much more congenial. He led their annual parades and inspected the new cadets; members of what he now called his Imperial Constabulary saluted him when he passed.

Norton I was a great believer in progress and innovation, and many of the ideas for which he was sometimes regarded as mad have become realities. He issued numerous proclamations proposing and then finally commanding the construction of a suspension bridge linking San Francisco and Oakland, complete with his own design sketches. His planned San Francisco terminus is within a block of where the Bay Bridge abuts now, and a plaque on it bears testimony to his foresight. He was also convinced that travel by air would one day become common, and commissioned panels of researchers and designers to create plans for airships.

The historical twilight of monarchy was gathering, however, and Norton made it part of his mission to restore whatever luster he could to it. He sent frequent cables to fellow rulers, offering surprisingly well-informed advice, or reflecting on the complex responsibilities of rulership. Many of the responses he got were in fact forgeries, created by his friends to make him happy, but many were not. King Kamehameha of Hawaii (known then as the Sandwich Isles) was so taken with the Emperor's insight and understanding that towards the end of his life he refused to recognize the U. S. State Department, saying he would deal only with representatives of the Empire.

Norton I died quite suddenly of apoplexy, on January 8, 1880, on the corner of California and Grant, on his way to a scientific conference. He left no heir. San Francisco went into a period of deep mourning for three days. Ten thousand people, from every walk of life, lined up to view his mortal remains; his funeral cortege was two miles long. At 2:39 that day, during his funeral, San Francisco experienced a total eclipse of the sun. Fifty-four years later, Norton's coffin was reinterred at Woodlawn Cemetery in Colma--once again, flags throughout the city were lowered and businesses closed their doors. About sixty thousand people attended the ceremony, which was accompanied by full military honors and dolorous taps.