[4] According to the 2021 census gazetteer files, Annawan has a total area of 2.14 square miles (5.54 km2), all land.

Mud Creek meandered through the area and Green River paralleled the current Interstate 80 to the north.

In 1850, a survey of the right-of-way for the Chicago, Rock Island and Pacific Railroad was made through Henry County.

At the turn of the twentieth century, a new channel of Green River was developed, drainage ditches were completed and tile installed.

Today, Annawan supports a variety of different businesses that serve Henry County and Interstate 80 travelers.

The aforementioned ethanol plant, Patriot Renewable Fuels, opened in 2007, providing Annawan with around 100 jobs.

Annawan supports one hotel, three gas stations, five restaurants/taverns, a grocery store, and a gift shop, to name a few different services available in the community.

[8] (In order of past to present) F. H. Slater, James Bice, S. C. Carpenter, W. S. Knowlton, Elmer Fitzkee, John Lamont, J. P. Paine, Dr. W. H. Webster, Dr. Robert White, Seth Moo, C. H. Mason, O. W. Nowell, George Dow, Hugh White, Dr. J. M. Young, Edward Doubler, Charles Verdick, Robert Pont, Arthur Quaife, Raymond Bollengier, Henry Nowers, Wilbur Hodgett, Dennis DeSplinter, and Kennard Franks (2001–2015), Scott Smith (2015–2016), Tim Wise (2016–present) Nearby Annawan is Johnson Sauk Trail Park, which includes a 60-acre lake with a maximum depth of 21 feet, and a small pond.

About a mile west of Annawan is Mud Creek, which serves as the midpoint for the Carol M. Guthrie 5 Kilometer (3.5 mi) run.

The yard game originated in Belgium (where it is known as krulbollen) and was brought over by Belgian immigrants to the United States in the late 19th and early 20th century.

[9] The game is also played in the nearby towns of Moline, Atkinson, Manlius, Geneseo, Kewanee, and Hooppole.