Question: Emory Nusz was born in the city that is the county seat of what county?

Context paragraphs:
Mason, Michigan: Mason is a city in the U.S. state of Michigan.  It is named after the state's first governor, Stevens T. Mason.  As of the 2010 census, the city population was 8,252.  It is the county seat of Ingham County.  Mason is the only city in the U.S. that serves as a county seat ahead of a state capital, with the capital of Lansing also in Ingham County.  Despite Mason being the county seat, many county offices and courtrooms are located in Lansing.

Cerro Gordo County Courthouse (Iowa): The Cerro Gordo County Courthouse is located in Mason City, Iowa, United States.  When Cerro Gordo County was created in 1855 and Mason City was selected to be the county seat.  Dissatisfaction in the western part of the county led the Iowa legislature to appoint three new commissioners who would move the county seat to Livonia.  A courthouse was built there.  A petition signed by over half of the citizens of the county requested that the county seat be moved back to Mason City.  Mason City also won the election in 1858 to decide the matter 155-48.  Two courthouses have stood in Mason City prior to the present Modernist structure that was occupied by the county in 1960.  It had been built as the Standard Oil Building, and was acquired by the county in 1959 for $159,400 and then remodeled for their use.

Emory Rains: Emory Rains (May 4, 1800 – March 4, 1878) was a lawyer, judge and political leader in the Republic of Texas and thereafter in the State of Texas.  Rains was born in Warren County, Tennessee, and moved to Texas in 1817.  Emory Rains held many public offices and his life was devoted to public service.  Rains was a Member of Texas Republic Senate from the District of Shelby and Sabine (1837–1839); a delegate to the Texas state constitutional convention (1845); a member of the Texas state house of representatives (1847–1848, 1851–1854); a member of the Texas state senate (1859).  In 1839, Rains was a prime supporter of the historic law creating a Homestead exemption in Texas.  In 1861, he stood with Sam Houston in opposition to secession from the union.  In 1866, Emory Rains rode a mule to Austin, Texas, for the purpose of getting a bill introduced to create Rains County, Texas.  Emory Rains died on March 4, 1878, of an apparent stroke, and is buried in the City Cemetery in Emory, Texas.  Both Emory, Texas, and Rains County, Texas are named for him.

Ellicott City, Maryland: Ellicott City is an unincorporated community and census-designated place, along with being the county seat of local government in Howard County, Maryland, United States.  It is part of the Baltimore Metropolitan Area.  The population was 65,834 at the 2010 census.  Founded in 1772, the town contains the B. & O. Railroad Museum's branch at the Ellicott City Station, built in 1830 as the first terminus of the initial line.  The downtown historic district is located in the valley of the small Tiber River, with its east end abutting the Patapsco River, which forms the Baltimore County line.  As of the 2000 census, Ellicott City surpassed Towson (county seat of neighboring Baltimore County) for the first time, as the largest unincorporated county seat in the country.

Johnston Library: The Johnston Library is a historic library located at 210 W. 10th St. in Baxter Springs, Kansas.  The building was constructed in 1872 to serve as a courthouse during Baxter Springs' unsuccessful attempt to become the Cherokee County seat.  Though Baxter Springs had lost an election to choose the county seat in 1869 to Columbus, supporters of both cities had attempted to fraudulently swing the election in their favor, and Baxter Springs hoped it could still become county seat in the future.  The building initially served as the county jail and sheriff's office until Columbus completed its jail in 1880.  After this, Baxter Springs ultimately gave up its attempts to become the county seat, and the building became its city hall.  In 1905, resident Niles P. Johnston bequeathed $5,000 to the city to start a library, and the city hall building was chosen to house it.

Emory, Texas: Emory is a city in Rains County, Texas, United States.  The population was 1,239 at the 2010 census.  It is the county seat of Rains County.  Previously known as Springville, the city and county are named after Emory Rains who was a legislator from the area.  Rains was the author of the Homestead Law of Texas which was later used as a model for the protection of homesteads throughout the United States.  Special legislation passed to create Rains County called for the citizens to vote on the location of the county seat and for that selected town to be renamed Emory.

Frederick, Maryland: Frederick is a city and the county seat of Frederick County in the U.S. state of Maryland.  It is part of the Baltimore–Washington Metropolitan Area.  Frederick has been an important crossroads community since it was located in colonial times at the intersection of an important north–south Indian trail, and east–west routes to the Chesapeake Bay both at Baltimore and what became Washington, D.C. and across the Appalachian mountains to the Ohio River watershed.  It is a part of the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area, which is part of a greater Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area.  The city's population was 65,239 people at the 2010 United States Census, making it the second-largest incorporated city in Maryland, behind Baltimore.

Emory Nusz: William Emory Nusz (November 2, 1859 – July 26, 1903) was an American professional baseball player who played in one game for the Washington Nationals of the Union Association during the 1884 season.  He was born in Frederick, Maryland and died in Baltimore, Maryland at the age of 44.

Emory C. Ferguson: Emory Canda Ferguson (March 5, 1833 – October 7, 1911) was an early pioneer of Washington State who helped create Snohomish County from Island County in 1861.  Along with Edson F. Cady, he was a founder of Snohomish, which would become the county seat from 1862 until 1896.  Over his life, Ferguson served as county commissioner, postmaster, a Washington state legislator, Speaker of the State House of Representatives, Snohomish City Council President, justice of the peace, and mayor of Snohomish, as well as realtor, saloon keeper, and store owner.  He was involved in many early plans to make Snohomish prominent, including a ferry for military use across the Snohomish River and a trail through the Cascade Mountains to reach a gold rush, few of which were successful.  Upon his death, Ferguson was eulogized as the "Father of Snohomish."

Rains County, Texas: Rains County is a county located in the U.S. state of Texas.  As of the 2010 census, its population was 10,914.  Its seat is Emory.  The county (and county seat) are named for Emory Rains, a Texas state legislator.

Supporting paragraphs: Emory Nusz Frederick, Maryland
Answer: Frederick County