In 1816, the grandfather was appointed by the General Assembly to be associate judge of the Circuit Court for Montgomery County, in which capacity he served for fifteen years.

Lewis Gunckel's maternal great-grandfather, John Martin Shuey's father, was elected to represent the Lancaster County, Pennsylvania Committee of Inspection to cooperate with the Continental Congress in the years preparatory to the American Revolution, although he died before the Declaration of Independence was signed.

At its dissolution, he refused to join in the Know-Nothing movement, but upon the organization of the Republican party he at once transferred his allegiance to it, being one of the first local members.

When his bill for soldiers' families relief was assailed — its constitutionality questioned and a plea of economy urged — Gunckel replied: We can economize elsewhere, retrench everywhere, and save enough to the state in its local and general expenses to make up the entire sum; but if not, we should bear it cheerfully, heroically.

He introduced a bill that established a State of Ohio soldiers' home for returning veterans and after his senate service was appointed by the Governor as its manager.

An act of Congress was approved March 31, 1865, appointing a Board of Managers of the National Homes for Disabled Volunteer Soldiers.

In the selection of a site for the Central Home, the Board of Managers looked at the rich and fertile Miami Valley, and entered into negotiations for the purchase of 540 acres (2.2 km2) of land, about three miles (5 km) west of the city of Dayton.

In 1871, Ulysses S. Grant's Secretary of the Interior appointed Gunckel special commissioner to investigate frauds upon the Cherokee, Creek and Chickasaw Indians.

He served on the military committee, became conspicuous in the House by his relentless opposition to public corruption and organized raids on the national treasury.

In 1874, Gunckel was unanimously nominated by his party for re-election, but the country was suffering from the financial Panic of 1873 and was torn by the temperance movement.

These brought about a political revolution in Ohio and resulted in the election of Democrat John A. McMahon, Gunckel's law partner.