Julius Hermann Kroehl (in German, "Kröhl") was a German American inventor and engineer.
 He invented and built the first submarine able to dive and resurface on its own, the Sub Marine Explorer, technically advanced for its era.
 His achievements in architecture, civil and mechanical engineering were also significant.
Julius Kahn (February 28, 1861 – December 18, 1924) was a United States Congressman who was succeeded by his wife Florence Prag Kahn after his death.
 Kahn was born in Kuppenheim, in the Grand Duchy of Baden, in what would become Germany.
Hy-Rib was a brand name for a product manufactured by the Trussed Concrete Steel Company.
 It is an engineering reinforcement system for floors, walls, and ceilings of buildings and houses.
 This product is a derivative of the Kahn Trussed Bar for beams and columns that was invented by Julius Kahn.
 Kahn engineered the Hy-Rib products and they were first manufactured in 1909.
Julius Mackerle (18 June 1909 Jevíčko, Moravia Austria-Hungary – 11 September 1988) was a Czechoslovakian inventor and automobile engineer.
The Trussed Concrete Steel Company was a company founded by Julius Kahn, an engineer and inventor.
 The company manufactured prefabricated products for reinforced concrete beams and steel forms for building reinforced concrete floors and walls.
 Kahn invented and patented a unique new technology reinforcement system of construction called the Kahn System that was stronger, more economical, and lighter than the existing old school technology used up to that point to construct buildings.
 The old method was to use plain straight smooth steel beams or loose rods or stirrups in concrete beams and floors.
 Kahn's new technology improved system used 45 degree tab flanges or "wings" permanently attached on steel beams that distributed the tension stress for overall improvement in strength of reinforced concrete.
Florence Prag Kahn (November 9, 1866 – November 16, 1948) was an American teacher and politician who in 1925 became the first Jewish woman to serve in the United States Congress.
 She was only the fifth woman to serve in Congress, and the second from California, after fellow San Franciscan Mae Nolan.
 Like Nolan, she took the seat in the House of Representatives left vacant by the death of her husband, Julius Kahn.
The Military Surplus Act (or Kahn-Wadsworth Act) was signed into US law by the 66th US Congress in 1920.
 Sponsored by Representative Julius Kahn (R) of California and Senator James Wolcott Wadsworth, Jr. (R) of New York, it distributed 25,000 surplus army trucks to state highway departments for road-building purposes.
The National Defense Act of 1920 (or Kahn Act) was sponsored by United States Representative Julius Kahn, Republican of California.
 This legislation updated the National Defense Act of 1916 to reorganize the United States Army and decentralize the procurement and acquisitions process for equipment, weapons, supplies and vehicles.
 It was passed by Congress on June 4, 1920.
The Kahn System is an industrial construction technique for reinforcement of buildings that was engineered and patented by Julius Kahn.
 The Kahn system is an industrial construction design using the Kahn Trussed Bar as the bases.
 This steel bar was a new type of reinforcing bar used in concrete and had unique engineered features to distribute stress.
Kahn was born in Münstereifel, Germany, March 8, 1874.
 He was raised in Detroit, Michigan.
 Kahn came to Detroit in 1881 from Germany with his family (five brothers and two sisters) when he was six years old, settling first in Baltimore, Maryland in 1880.
 His father Joseph (1860–1924) was a rabbi and ran a restaurant.
 Kahn helped in his father's restaurant business and sold newspapers.
 His mother Rosalie was skilled in music and art.
 Kahn went to the Detroit Public Schools where he received his elementary schooling, doing the normal four-year high school in three years.

Question: Julius Kahn, an engineer and inventor was born in what Country?
Answer: Germany