Under the dome, masters entered their vessels by submitting their manifest, and verifying this manifest by oath in the presence of officers, before a permit to discharge was granted. Masters clearing their vessels filed a sworn manifest of their outward lading described by kind, quantity, value, and destination, before a clearance and a bill of health were issued. Meanwhile, importers, and licensed brokers worked with other officials to release their goods.

Beyond public view, the rest of the building up to the sixth floor was filled with the offices of a sprawling bureaucratic machine that carried out a wide array of fiscal, regulatory, and statistical duties.

On a given day the customs service processed the entry of fifteen vessels, from the big English, French, and German liners, to smaller freight steamers, and sailing ships. Once a ship entered the port they were under the charge of the surveyor’s office, which was organized into five divisions that handled the inspection, weighing, and measuring of all goods entering the port. In 1908, the first year after the building’s completion, the customs service entered over 4,500 vessels from over thirty different countries carrying eight hundred million dollar’s worth of goods.

The principal articles entering the port were raw materials, foodstuffs, and partially manufactured goods. The city received three-fourths of the country’s coffee, sugar, and cocoa, and nearly half of the tobacco and tea. It received more than three-fourths of silk, cotton, and wool manufactures. In addition, it received 90 per cent of the India rubber, books, diamonds and precocious stones. In the course of a calendar year over half of the nation’s foreign trade in value entered the port.

In the period in which the custom house was built its officers administered the highest protective tariff in the nation’s history, reaching nearly nearly fifty percent on dutiable goods. The complex task of determining the specific duty on goods fell to the appraiser’s office, which was divided into ten divisions. To each division was assigned an extraordinary range of goods which needed to be carefully examined before they could appraise their market value at the time of exportation.

For the most part the public was only dimly aware of the scale of this operation, and its own experience of the customs service was extremely unpleasant. Shortly after the completion of the custom house, the customs service instituted a new inspection regime for all incoming passengers. While still on board, every person entering the port was required to declare under oath all goods that were dutiable, and as one journalist put it, “leave the rest to luck, their conscience, and the Customs Inspectors.”

After landing, they were patted down, their trunks were opened, and their baggage inspected. In a cartoon that summed up the experience of going through customs, passengers are depicted being thrown out of a chute, dazed as to what just happened. The loudest outcry came from wealthy tourists laden with luxuries purchased abroad, but it was an experience that offended citizen, tourist, and immigrant alike. A returning traveler noted that the “whole disagreeable farce in which he figures makes him feel like a thief and a fool; and he cannot even laugh at its absurdity, because he is the victim of the joke.”

From his perch in the monumental new headquarters, the collector rejected these pleas. As the gatekeeper of the port, he was entrusted with the solemn duty to protect the revenue. “We will not hesitate to strip a passenger to the skin if we consider it necessary to prevent smuggling,” he proclaimed. “It is within the legal province of the government to search every person who enters this country if our suspicions are aroused, and no good citizen should object to Uncle Sam getting his rights.”

Today the custom house is a cherished architectural landmark, but when it was built it was a fearsome symbol of federal authority over the port and of the high tariff wall that surrounded the nation.