1830 Census: 
Henry Dowling Hillsboro (Loudoun) VA, male 20-29 females: none 
Henry Darling Smithfield (Providence) RI males: 10-14,15-19,20-29,40-49, females: 10-14,50-59 
Henry Darling Smithfield (Providence) RI males: 60-69 females: 60-69 
Henry Durling Sempronius (Cayuga) NY males: 40-49 females: 30-39 
Henry Darling Bucksport (Hancock) ME males: 5-9,30-39 females: 0-4,5-9(2),10-14,20-29,30-39 
Henry Darling Kingston (Ulster) NY males: 5-9,40- 49,50-59 females: 0-4(2),40-49,60-69 
Henry Duling  Middletown (Frederick) MD males: 40-49 females: 50-59,80-89, Adam Darling lived next door 
Henry J Doling Flatbush (Kings) NY males: 0-4,5-9,30-39 females: 5-9,10-14,20-29 
Henry Durling  Newtown (Queens) NY (name given but no counts indicated) 
H. Dowling Charleston (Charleston) SC males: 40-49 females: 20-29 

1840 Census: 
H.M. Dowling New Albany Circuit (Floyd) IN males:0-4,30-39 females:15-19,30-39 
H. Darling New Orleans (Orleans) LA males:30-39, females:20-29 
H.G. Darling West Troy, Watervliet (Albany) NY males: 0-4,20-29 females: 0-4,15-19,20-29(2) 

1850 Census: 
Henry Dowling N.Brunswick Twp (Middlesex) NJ b.1810 IR laborer living in home of Richard Clark 
Henry Dooling St.Louis( St.Louis) MO b.1823 IR blacksmith, Elizabeth age 60 IR, John age 29 IR California trader, Thompson Logan age 28 ST blacksmith

TO FIND: Immigrant Ancestors, Birth/Death Date/Place, Censuses (NOTE: unknown if he ever lived in the U.S.) 

All that is really known about Henry is from the 1838 christening of his son Pat. Unknown if Henry ever lived in the U.S.

Historical
1819: France - Theodore Gericault paints his masterpiece The Raft of the Medusa, and exhibits It in the French Salon of 1819 at the Louvre
1819: Singapore, England - The modern city of Singapore is established by the British East India Company
1820: Liberia - Liberia founded by the American Colonization Society for freed American slaves
1820: United States - Missouri Compromise admits Missouri as a slave state and Maine as a free state
1821-1830: Greece, Turkey - Greece becomes the first country to break away from the Ottoman Empire after the Greek War of Independence
1821: Mexico, Spain - Mexico gains Independence from Spain with the Treaty of Cordoba
1821: Peru, Spain - Peru declares Its Independence from Spain
1822-1823: Mexico - First Mexican Empire, as the first post-independent Mexican government, ruled by Emperor Agustin I of Mexico
1822: Brazil, Portugal - Prince Pedro of Portugal proclaimed the Brazilian Independence on September 7, on December 1, he was crowned as Emperor Dom Pedro I of Brazil
1823-1887: England, Burma - The British Empire annexed Burma (now also called Myanmar) after three Anglo-Burmese Wars
1825-1828: Argentina, Brazil, Uruguay - The Argentina-Brazil War results in the Independence of Uruguay
1825: United States - Erie Canal opened connecting the Great Lakes to the Atlantic Ocean
1826-1828: Russia, Iran - After the final Russo-Persian War, the Persian Empire took back territory lost to Russia from the previous war
1827: England - Death of William Blake, an English poet, painter, and printmaker who Influenced literature
1828-1829: Russia, Turkey - Russo-Turkish War (ninth of ten), Russian victory
1830: Belgium, Netherlands - The Belgian Revolution in the United Kingdom of the Netherlands led to the creation of Belgium
1830: Colombia, Venezuela, Ecuador - Greater Colombia dissolved and the nations of Colombia (including modern-day Panama), Ecuador, and Venezuela took Its place
1830: France - July Revolution in France
1830: Poland, Russia - November Uprising in Poland against Russia
1830: United States - The Church of Jesus Christ of Latter Day Saints is established on April 6, 1830
1831-33: Egypt - Egyptian-Ottoman War
1831: France, Algeria - France Invades and occupies Algeria
1833-1876: Spain - Carlist Wars in Spain
1833: England - Slavery Abolition Act bans slavery throughout the British Empire
1834-1859: Russia - Rebellion led by Imam Shamil in Russian-occupied Caucasus
1834: Germany - The German Customs Union is formed
1834: Spain - Spanish Inquisition officially ends
1835-1836: United States, Mexico - The Texas Revolution in Mexico resulted in the short-lived Republic of Texas
1836: United States, Mexico - The Battle of the Alamo
1837-1838: Canada - Rebellions of 1837 in Canada
1837-1901: England - Reign of Queen Victoria is considered the apex of the British Empire and is referred to as the Victorian era
1838-1840: Central America - Civil war in the Federal Republic of Central America led to the foundings of Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica