Question: Which continent, located almost entirely within the Northern and Western Hemispheres, did Thaddeus Radzilowski lecture in?

Context articles: Lava Bed Mountains
Thaddeus Radzilowski
George Washington Memorial Parkway
Campgaw Mountain
Garland, Texas
Plainfield (town), Wisconsin
North America
Himalayan states
Crawford Notch
Piast Institute

The Lava Bed Mountains are located in the Mojave Desert in southeastern California, United States.
 The mountains lie in a northwest-southeasterly direction, and are located almost entirely within the Marine Corps Air Ground Combat Center Twentynine Palms, which is a restricted area.
 The mountains reach a height of 4488 ft above sea level at Argos Mountain, and are found at the northwestern end of the Bullion Mountains.
 Gays Pass is located at the southern end of the chain, with the Rodman Mountains to the northwest.
 The Lava Bed Mountains are approximately 11 mi , and lie in the arid climate zone, characterized by little rainfall.
Thaddeus C. Radzilowski or Tadeusz Radziłowski (born February 4, 1938 in Detroit) is an award-winning Polish-American historian, scholar, author, professor and co-founder of the Piast Institute, a national institute for Polish and Polish-American affairs.
 Dr. Radzilowski's work has focused on Poland and other Central and Eastern European nations, including Russia.
 He has written extensively on the histories of these regions as well as the migration of peoples from Central and Eastern Europe, with special emphasis on social history and historiography.
 He has lectured widely in Europe and North America and has published more than 100 monographs, edited collections, journal articles, book chapters and scholarly papers.
 In 1999, the President of Poland presented Dr. Radzilowski with the country’s high civil honor of the Order of Merit of the Republic of Poland for distinguished contributions to the dissemination of Polish culture in the world.
The George Washington Memorial Parkway, colloquially the G.W. Parkway, is a 25 mi parkway that runs along the south bank of the Potomac River from Mount Vernon, Virginia, northwest to Langley, Virginia, and is maintained by the National Park Service (NPS).
 It is located almost entirely within Virginia, except for a short portion of the parkway northwest of the Arlington Memorial Bridge that passes over Columbia Island within the District of Columbia.
Campgaw Mountain is the northernmost ridge of the volcanically formed Watchung Mountains, straddling the border of Franklin Lakes, Oakland, and Mahwah in Bergen County, New Jersey, United States.
 Located almost entirely within the bounds of Campgaw Mountain Reservation, the mountain offers numerous outdoor recreational opportunities, including the only ski slope in the Watchungs.
 Campgaw Mountain is commonly considered to be part of the greater Ramapo Mountains region, but the flora and geology of the mountain is quite different from the surrounding area and more closely resembles the nearby Preakness Range to the south.
Garland is a city in the U.S. state of Texas.
 It is a large city northeast of Dallas and is a part of the Dallas–Fort Worth metroplex, as well as a suburb of Dallas.
 It is located almost entirely within Dallas County, except a small portion located in Collin and Rockwall Counties.
 As of the 2010 census, the city had a population of 226,876, making it the 87th-most populous city in the United States of America and the 12th-most populous city in the state of Texas.
 Garland is second only to the City of Dallas in Dallas County by population and has easy access to downtown Dallas via public transportation including two Dart Blue line stations and buses.
Plainfield is a town in Waushara County, Wisconsin, United States.
 The population was 533 at the 2000 census.
 The Village of Plainfield is located almost entirely within the town.
 The ghost town of West Plainfield (still the present day site of the Town of Plainfield town hall) is located in the town.
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere; it is also considered by some to be a northern subcontinent of the Americas.
 It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.
The Himalayan states are a group of countries straddling the Himalayan mountain range in Asia.
 The area is divided between the Western Himalaya and the Eastern Himalaya.
 Two sovereign states, Nepal and Bhutan, are located almost entirely within the mountain range.
 The range also covers the southern Tibetan Autonomous Region of China, the Indian Himalayan states of North and Northeast India and northern Pakistan.
Crawford Notch is a major pass through the White Mountains of New Hampshire, located almost entirely within the town of Hart's Location.
 Roughly half of that town is contained in Crawford Notch State Park.
 The high point of the notch, at approximately 1900 ft above sea level, is at the southern end of the town of Carroll, near the Crawford Depot train station and Saco Lake, the source of the Saco River, which flows southward through the steep-sided notch.
 North of the high point of the notch, Crawford Brook flows more gently northwest to the Ammonoosuc River, a tributary of the Connecticut River.
The Piast Institute is a national research and policy center for Polish and Polish-American affairs based in Hamtramck, Michigan, in the United States, an enclave located within the city of Detroit.
 The institute was founded in 2003 by Dr. Thaddeus Radzilowski and Mrs. Virginia Skrzyniarz.
 With a board of directors composed of Polish-American leaders, an international network of Institute Fellows, and a staff led by Dr. Radzilowski as president and Mrs. Skrzyniarz as executive vice president, Piast Institute has evolved into the only think tank in North America devoted to Polish and Polish-American affairs.