Longworth began a law practice in Cincinnati after being admitted to the Ohio bar in 1894.
His political career began with a position on the city's Board of Education in 1898.

As the protégé of Republican boss George B. Cox, Longworth was elected to the Ohio General Assembly, serving in the Ohio House of Representatives in 1899 and 1900, then in the State Senate from 1901 to 1903.
In 1902 he was instrumental in writing and passing the Longworth Act, a bill regulating the issuance of municipal bonds, which has been labeled "one of the most successful laws in Ohio's history."
Longworth was elected to the United States House of Representatives from the First Congressional District of Ohio which included the city of Cincinnati and the surrounding counties.

Longworth, a bachelor when he entered Congress, married Alice Lee Roosevelt, the daughter of President Theodore Roosevelt, on February 17, 1906, in a White House wedding that received wide-spread public attention Their only child, Pauline, was born in 1925 (and died at age 31).

Throughout his political career, Longworth championed issues regarding foreign affairs and the protective tariff.

As the progressive Republicans pulled apart from the conservatives in 1910–12, Longworth sided with the conservatives.
When they bolted from the party in the 1912 election to support Theodore Roosevelt and establish their own party, Longworth, along with many of Roosevelt's closest political allies, remained firmly behind Republican standard-bearer President William Howard Taft.
Longworth agreed more with Taft than Roosevelt on critical issues like an independent judiciary and support for business.

As a result of the Republican Party rift, Longworth and his wife Alice found themselves on opposite sides of the divide in the fall campaign.
She actively supported her father's third-party presidential candidacy, even though her husband was running for reelection on the Republican ticket.
Longworth narrowly lost his House seat to Democratic challenger Stanley E. Bowdle.
Longworth began a law practice in Cincinnati after being admitted to the Ohio bar in 1894. His political career began with a position on the city's Board of Education in 1898.
As the protégé of Republican boss George B. Cox, Longworth was elected to the Ohio General Assembly, serving in the Ohio House of Representatives in 1899 and 1900, then in the State Senate from 1901 to 1903. In 1902 he was instrumental in writing and passing the Longworth Act, a bill regulating the issuance of municipal bonds, which has been labeled "one of the most successful laws in Ohio's history." Longworth was elected to the United States House of Representatives from the First Congressional District of Ohio which included the city of Cincinnati and the surrounding counties.
Longworth, a bachelor when he entered Congress, married Alice Lee Roosevelt, the daughter of President Theodore Roosevelt, on February 17, 1906, in a White House wedding that received wide-spread public attention Their only child, Pauline, was born in 1925 (and died at age 31).
Throughout his political career, Longworth championed issues regarding foreign affairs and the protective tariff.
As the progressive Republicans pulled apart from the conservatives in 1910–12, Longworth sided with the conservatives. When they bolted from the party in the 1912 election to support Theodore Roosevelt and establish their own party, Longworth, along with many of Roosevelt's closest political allies, remained firmly behind Republican standard-bearer President William Howard Taft. Longworth agreed more with Taft than Roosevelt on critical issues like an independent judiciary and support for business.
As a result of the Republican Party rift, Longworth and his wife Alice found themselves on opposite sides of the divide in the fall campaign. She actively supported her father's third-party presidential candidacy, even though her husband was running for reelection on the Republican ticket. Longworth narrowly lost his House seat to Democratic challenger Stanley E. Bowdle.
Nicholas Longworth