General Wayne A. Downing Peoria International

Caterpillar Inc. was created in 1925 by the merger of two California tractor companies — the Holt Manufacturing Company of Stockton and the C. L. Best Tractor Company of San Leandro. Holt had built the world's first commercially successful tracked tractor in 1904; legend has it that a Holt photographer watching the prototype crawl across a field said it moved "like a caterpillar," and the name stuck. The combined company moved its headquarters from California to Peoria in 1928 to be closer to its largest customer base, and Peoria has been the home of Caterpillar manufacturing and engineering for almost a century since. The Caterpillar Visitors Center opened in 2012 in a modern building on the downtown Peoria riverfront. Its centerpiece is a real Cat 797F Mining Truck — one of the largest production trucks in the world. The 797F carries a 400-ton payload, weighs 1,400 tons fully loaded, runs on 24-foot Michelin tires (each tire weighs 12,000 pounds and costs about $42,000), and burns one gallon of diesel per quarter-mile. Visitors can climb into the cab. The bed of the truck has been converted into a small theater — the "Future Theater" — where a film about Cat's role in global infrastructure plays. The Heritage Gallery traces the company from the 1904 Holt tractor through the British Mark I tank of WWI (which used Holt-style continuous tracks), through the Hoover Dam, the Panama Canal widening, the Three Gorges Dam, and into modern autonomous mining and electrification. Admission is free. The Center is open Tuesday through Saturday, 10am to 3:30pm. Note: Caterpillar moved its corporate headquarters to suburban Chicago (Deerfield) in 2017 and again to Irving, Texas in 2022. Manufacturing, engineering, the world headquarters of the Cat Foundation, and most senior R&D remain in the Peoria area.

Abraham Lincoln arrived in Springfield in 1837 as a 28-year-old lawyer. He married Mary Todd here in 1842, raised four sons here, practiced law and rode the Eighth Judicial Circuit for nearly 25 years, gave the "house divided" speech here in 1858, and left for Washington as president-elect in 1861. After his assassination on April 15, 1865, the funeral train carried him back through eleven cities to Springfield. He has been here ever since. Lincoln's Tomb in Oak Ridge Cemetery is a 117-foot granite obelisk designed by sculptor Larkin Goldsmith Mead, built with public donations between 1868 and 1874. Lincoln is buried in a crypt under the obelisk along with Mary Todd and three of their four sons — Edward, William, and Thomas ("Tad"). Robert, the only one who survived to adulthood, served as Secretary of War under Garfield and is buried at Arlington. At the entrance to the tomb a bronze bust of Lincoln has a polished gleaming nose — generations of visitors have rubbed it for luck. Oak Ridge is the second most-visited cemetery in the United States, after Arlington. The Old State Capitol (1837-1840, served as the State House until 1876) is downtown — a low Greek Revival building of locally quarried Sugar Creek limestone. Lincoln gave the "A house divided against itself cannot stand" speech here on June 16, 1858, accepting the Republican nomination for the US Senate. He also lay in state here after his assassination. The current Illinois State Capitol (1888) sits two blocks SW — its dome rises 405 feet, 74 feet taller than the US Capitol in Washington, intentionally so. The Lincoln Home (Eighth and Jackson, ~6 blocks SE of the Old State Capitol) is the only home Lincoln ever owned. The Lincolns lived there from 1844 until 1861. It is now a National Park Service unit — Lincoln Home National Historic Site — and the surrounding four-block neighborhood has been restored to its 1860 appearance.

Starved Rock is the closest thing the Midwest has to a slot-canyon park. At the end of the last Ice Age — somewhere between 14,000 and 17,000 years ago — a catastrophic flood of glacial meltwater called the Kankakee Torrent ripped through this stretch of central Illinois. The flood found the softest layer of bedrock (St. Peter Sandstone, deposited as beach sand 470 million years ago) and gouged 18 narrow canyons into the south bank of what is now the Illinois River. The result is a 2,630-acre park of vertical sandstone walls, mossy seeps, and waterfalls fed by spring runoff — landforms that look like they belong in Utah, transplanted to the middle of corn country. It is the most visited state park in Illinois (over 2 million visitors a year) and was the state's second park, purchased in 1911 to keep it from being quarried for sandstone. The "Starved Rock" itself is a 125-foot sandstone butte at a bend in the Illinois River. Native American oral tradition says the name comes from an 18th-century siege — a band of Illiniwek warriors took refuge atop the butte to escape Ottawa and Potawatomi war parties avenging the 1769 killing of Chief Pontiac, and starved there. French explorers Jacques Marquette and Louis Jolliet passed through this stretch in 1673; the French built Fort St. Louis on top of the butte in 1682-83. The Civilian Conservation Corps built much of the trail infrastructure (stone stairways, shelters, the lodge) in the 1930s. The site was designated a National Historic Landmark in 1966. Immediately downstream of the butte is Starved Rock Lock and Dam — one of eight in the Illinois Waterway that take barges over the 163-foot drop from Lake Michigan to the Mississippi. Bald eagles winter on the open water below the dam; the park is one of the best eagle-watching sites in the Midwest December through February.

Arsenal Island sits in the middle of the Mississippi River between Rock Island, Illinois and Davenport, Iowa — 946 acres of land at the strategic point where the Mississippi makes its sharpest east-flowing turn. Fort Armstrong was built here in 1816, named for Secretary of War John Armstrong. During the Civil War the island held one of the largest Confederate prisoner-of-war camps in the North — roughly 12,000 prisoners passed through and about 1,961 died of disease. The Confederate Cemetery is on the south side of the island, alongside the Rock Island National Cemetery for Union dead. Rock Island Arsenal was established in 1862 by act of Congress. It is still active — the largest government-owned and operated arsenal in the United States, employing 6,000+ people in the Quad Cities area. The 19th-century limestone arsenal shops on the east end of the island were designated a National Historic Landmark district in 1989. Two pieces of American transportation history happened here. In 1856 the first railroad bridge ever built across the Mississippi River was completed at Rock Island. Two weeks after it opened, the steamboat Effie Afton hit one of its pillars; both the boat and a span of the bridge caught fire. The Effie Afton sank and her owners sued the railroad. The case was tried in Chicago in 1857, and the railroad's lawyer was Abraham Lincoln. The jury hung, leaving the bridge standing. The principle that bridges could be built across navigable rivers was established for the rest of the country. Lock and Dam 15, immediately downstream of the island, is the largest roller dam in the world: 1,203 feet long, nine 109-foot roller gates plus two overflow gates. Built 1932-34, it was the first of 29 lock-and-dam complexes in the Upper Mississippi Nine-Foot Channel Project — the New Deal-era engineering project that converted 650 miles of free-flowing river into a controlled commercial waterway between St. Louis and Minneapolis.