John Henry was born in November 1750 in Vienna, Maryland, United States, the son of Colonel John Henry and Dorothy Rider. He was the grandson of Revolutioner John Henry, a Scotch Presbyterian minister who emigrated to America early in the eighteenth century, and of his wife Mary (King), daughter of an Irish baronet.
John Henry attended West Nottingham Academy, in Cecil County, until prepared to enter the College of New Jersey (now Princeton University), from which institution he was graduated in 1769. During the next six years he was engaged in the study of law and completed his legal training at Middle Temple, London.
John Henry sailed from England in 1775, enjoyed much popularity on his return to Maryland, was soon elected to the General Assembly, was chosen a delegate to the Continental Congress on December 22, 1777, took his seat in that body January 20, 1778, and with the exception of an interval of three years (1781 - 1784) when he served in the Maryland Senate, held it until 1787. He had been in Congress less than one week when he wrote the governor of his state that the army for want of pay, clothes, and provisions was decreasing every hour, not by one or two at a time, but from seven to twelve. Against these conditions he directed his efforts. He procured funds for the Maryland recruiting sendee, appealed to the governor for clothing and other supplies, and advocated the concentration of the army for "strengthening the hands of General Washington. ”
Henry served on many committees, such as that to procure flour for the army, to procure aids and supplies from France, on ways and means, on taxes, on a motion for erecting new states out of the western territory. When Virginia and other states had yielded with regard to their claims to the western lands, Henry voted in the Maryland Senate to authorize the Maryland delegates to ratify the Articles of Confederation.
When in December 1788, after the adoption of the federal Constitution, the two houses of the General Assembly of Maryland met in joint session for the first election of United States senators, Henry received the required majority on the second ballot and Charles Carroll of Carrollton was elected his colleague on the third ballot. Henry took his seat in the Senate April 20, 1789, and when lots were cast to determine who should serve for two years, who for four years, and who for six years, he drew the six-year term. Disregarding instructions by the Assembly, he voted, in March 1792, against a resolution for open sessions of the Senate. The House of Delegates censured him, but he was reelected for the term commencing March 4, 1795. Two years later, November 13, 1797, the Maryland Assembly elected him governor of the state. He resigned his seat in the Senate to accept that office, served a full term of one year, refused to be considered for reelection, retired in ill health from public life, and died within a month on his estate along the Nanticoke River in Dorchester County.
John Henry was a member of the Republican party; the Maryland State House of Delegates from 1777 to 1780; the Maryland State Senate from 1780 to 1790; and United States Senate from Maryland from 1789 to 1797.
Henry was recognized by his associates as a man of integrity and was highly respected for his knowledge of law.
On March 6, 1787, John Henry married Margaret Campbell, daughter of John and Elizabeth (Goldsborough) Campbell. They had two sons.
