After the war Loudon printed the Laws of the City of New York, and later promoted ratification of the proposed Constitution by publishing selected essays of The Federalist Papers in his newspaper.

[1][2][3][4][5] In October 1753 he owned and operated a general store on Water Street near the Old Slip Market in New York City, where he sold an assortment of wares, including powder and shot, pots and kettles, and a variety of ready-made coats and breeches, in the latest fashions.

While there were a number of bookshops that came and went in New York, only Samuel Loudon and Hugh Gaine continued to run their book shops by the turn of the century.

Paine's popular but controversial work was highly critical of the British Crown, Parliament and their dealings with the colonies, and strongly advocated the rebellion and the cause for American independence.

Loudon's fellow Whigs were surprised and alarmed at his action and subsequently a meeting was called where the concerned parties met.

[2][15] Loudon founded and published a newspaper in New York City, The New-York Packet and The American Advertiser, on January 4, 1776, which he had printed on Thursday mornings.

He took on the responsibility of becoming the local postmaster as part of the duties of a printer, where he managed the handling of mail and decided on the various postal routes.

[2] In 1779 The Supreme Executive Council of Pennsylvania procured a subscription to London's New York Packet, and Secretary Mallack wrote to have it dispatched on a regular basis, "in order to have the files compleat" to which Loudon replied as follows : FIshkill, 25th Feby.

[23][24] A ledger of Postmaster General Benjamin Franklin notes that the revenue raised by two of the thirteen post offices for the first report period under the Americans on July 28, 1777.

Printings of the manuscript copy of Broeck's address were also forwarded to the Continental Congress on December 28, with notice that they had intended to have it translated into German.

In 1781, Washington dispatched a letter to Loudon, dated July 10, requesting that Loudon publish a proclamation in his "useful newspaper", The New York Packet, informing the inhabitants of the Fishkill area that his army thereabouts "remains in its present Position, from Day Break till Noon", and that two market places will be open to aid in the supply of that army.

[31] Several newspapers carried the same exact proclamation, with ornamental framing, in the headings, including Loudon's New York Packet and the American Advertiser.

Ten days after Cornwallis' surrender Loudon featured the event in celebratory tones on the front page of the November 1, 1781 issue of The Packet.

Just below the heading the Latin phrase LAUS DEO was inscribed in large bold letters, meaning "Praise be to God".

[35] In 1783 Loudon printed the famous Newburgh letter[i] in with a pamphlet called A Collection of Papers relating to Half Pay to the Officers of the Army, which he had reprinted several times.

The advertisement for the sale of John Jacob Astor's musical instruments was periodically published by Loudon in his newspaper to March 10, 1785.

[39] In 1784 Loudon printed and published a twenty-eight page tract, entitled A Letter from --[j] in London, to his friend in America, on the subject of the slave trade : ....

[40] Beginning in 1785 Loudon became an active member of New York's Saint Andrew Society and for many years was an elder of the Scotch Presbyterian Church on Cedar Street.

Not understanding its cause and knowing no other recourse, Presbyterian minister John Mitchell Mason commissioned Loudon, though retired, to print a sermon he had written, which was read in New York on a day set aside for public fasting and prayer for the people in Philadelphia.

[46] The idea for the need of a strong federal government to unify the newly established states was promoted in the 1780s by Alexander Hamilton, James Madison, John Jay and other members of the Federalist Party in a series of eighty-five essays in support of the ratification of the United States Constitution, commonly referred to as The Federalist Papers.

[53][54] After the United States Constitution was ratified on June 21, 1788 the competition over the public printing contract for the newly established government became stringent among the leading printers in New York.

Along with Samuel Loudon, there was Francis Childs, Thomas Greenleaf, Archibald McLean, and John Fenno who all submitted petitions for this important contract.

[49] Beginning in 1789, however, Francis Childs and John Swaine were awarded contracts for printing the laws and various official documents for the United States Government, including the Standing Rules and Orders of the House of Representatives, 1789 and the Acts Passed at the First Congress, 1789.