From Cod, by Mark Kurlansky (Penguin, 1998), pp. 78-80:
By the eighteenth century, cod had lifted New England from a distant colony of starving settlers to an international commercial power. Massachusetts had elevated cod from commodity to fetish. The members of the “codfish aristocracy,” those who traced their family fortunes to the seventeenth-century cod fisheries, had openly worshiped the fish as the symbol of their wealth. A codfish appeared on official crests from the seal of the Plymouth Land Company and the 1776 New Hampshire State seal to the emblem of the eighteenth-century Salem Gazette—a shield held by two Indians with a codfish overhead. Many of the first American coins issued from 1776 to 1778 had codfish on them, and a 1755 two-penny tax stamp for the Massachusetts Bay Colony bore a codfish and the words staple of Massachusetts.
When the original codfish aristocrats expressed their wealth by building mansions, they decorated them with codfish. In 1743, shipowner Colonel Benjamin Pickman included in the Salem mansion he was building a staircase decorated with a gilded wooden cod on the side of each tread. The Boston Town Hall also had a gilded cod hanging from the ceiling, but the building burned down, cod and all, in 1747. After the American Revolution, a carved wooden cod was hung in the Old State House, the government building at the head of State Street in Boston, at the urging of John Rowe, who, like many of the Boston revolutionaries, was a merchant. When Massachusetts moved its legislature in 1798, the cod was moved with it. When the legislature moved again in 1895, the cod was ceremoniously lowered by the assistant door-keeper and wrapped in an American flag, placed on a bier, and carried by three representatives in a procession escorted by the sergeant-at-arms. As they entered the new chamber, the members rose and gave a vigorous round of applause.