[16] Seymour was established and mapped out on April 27, 1852, by Meedy and Eliza Ewing Shields, near the 1809 Indian Treaty Corner and about two miles south of Rockford, Indiana.

[21] Meedy Shields placed advertisements in the nearby Cincinnati and Louisville newspapers, offering a free lot and $100 to any congregation willing to establish a church in the city.

On April 20, 1860, an Adams Express package shipped from Nashville, Tennessee, and addressed to "Hannah Johnson [care of] Levi Coffin" burst open at Seymour while en route to Cincinnati.

[24][25] Due to its strategic location along rail lines, and with the large cities of Indianapolis, Chicago, and Detroit to the north and St. Louis to the west, Seymour was an important waypoint for the movement of men and supplies to the front during the war.

Despite southern Indiana's strong Copperheads political sentiment,[26] the city of Seymour and the surrounding area raised three separate infantry units for service in the Union Army.

Company H of the 6th Indiana Infantry Regiment was also raised in Seymour, and commanded by Captain Fielder A Jones, who would end the war as a Brevet Brigadier General.

Shields had organized and trained many local and mounted militia units, and in Love's words, "rendered invaluable service" during the Morgan's Raid crisis.

Colonel Heffron, who was poorly regarded by the men of the regiment, was also dismissed from the army and replaced by Major Samuel T Wells, a Vallonia, Indiana, native, Mexican-American war veteran, and former Jackson County Sheriff.

It was committed by the local Reno Gang, on October 6, 1866, just east of town, starting in the Adams Express Company car of the Ohio and Mississippi Railroad.

[47] On October 6, 1896, the Democratic Nominee for President, William Jennings Bryan, stopped in Seymour and gave a short campaign speech at Shields Park to a crowd.

[55] On October 22, 1908, William Howard Taft, the Republican Nominee for President of the United States, made a campaign speech in Seymour to 10,000 people at the Chestnut Street railroad crossing during his whistle-stop tour of Indiana two weeks before the election.

[64] While campaigning in Indiana just prior to the 1920 President Election, Republican Nominee, Warren G. Harding, gave a speech in Seymour on October 15 to an enthusiastic crowd regarding foreign policy and his opposition to the League of Nations.

[65][66] In 1934, Seymour police officer John Pfaffenberger was shot and killed by three assailants after he attempted to stop their car after they stole a few dollars' worth of fuel from a gas station east of town.

Employees Theresa Osborne, Mike Reece, and Carrie Croucher all from Rose Acre with ties to founder David Rust died under mysterious circumstances.

This, with the release of his "Rain on the Scarecrow" single and music video, increased awareness of the plight of rural American farmers in general and life in Seymour specifically.

[111][112][113] Despite efforts from local community leaders, the city of Seymour and then-mayor John Burkhart ordered the leveling of the historic Vondee Theater on September 24, 1993.

Governor John Mutz and community leaders at the Jackson County Industrial Development Corporation, Aisin constructed a factory in Seymour in 1986,[120] with production beginning in 1989 with wide public support.

[124] The Seymour Diamond Crossing is a good place to also watch the east-west railroad line, which CSX upgraded in 2016 for reliable higher speed operation.

The Mellencamp family donated $50,000 to help turn the former parking lot into a green space so more people could enjoy the mural painted by artist Sue Bliss.

[128] In October 2024, Indiana Attorney General Todd Rokita issued a civil investigative demand to ensure the city complies with state immigration policies.

In response, Seymour Common Council member Drew Storey held an impromptu community meeting to address concerns about the city's rapidly growing population.

[138] Seymour experiences a humid subtropical climate (Köppen classification "Cfa") characterized by high temperatures and evenly distributed precipitation throughout the year.

Summers are influenced by moist maritime airflow, leading to warm, oppressive nights and convectional thunderstorms, with tropical cyclones enhancing rainfall in some regions.

New immigration cases filed for people in Jackson County—a proxy for migrant arrivals—jumped to 435 in the fiscal year ended in September, from 66 in 2021, according to the Transactional Records Access Clearinghouse at Syracuse University.

The first Oktoberfest was organized by the Seymour Chamber of Commerce and featured Bavarian music, carnival rides, food and exhibit booths, parades, a hot air balloon race, baby contest and a Biergarten.

Meedy Shields Blish (1855–1922) was inspired to provide a local place of comfort and relaxation to area farmers while they were bringing produce and grain to market in the city.

[185] The T. Harlan and Helen Montgomery House is a grade five historic building of Dutch Colonial Revival design located at 628 North Poplar Street has 5 bedrooms and 2 and a half baths.

[200] Since his election, in addition to his official duties, Nicholson has joined the board of directors for Main Street Seymour, Indiana and regularly contributes to the local newspaper.

[202] A chronological list of mayors of the city of Seymour includes;[203] Over the past two decades, Jackson County, Indiana, has consistently shown strong support for Republican candidates in presidential elections.

Interstate merged into Midland United Company, leased to Indiana Railway, and all trains south of Seymour stopped running to Louisville in September 1939.