Was born in Belmont county, Ohio, March 12th, 1802. His father, Alexander McWilliams, was born on shipboard, on the way to America, whither his parents were sailing, in the year 1776. He is of Scotch descent. His parents located at Brownsville, Pennsylvania, in which state he received his early education. At the age of twenty-two he was married to Miss Jane Paxton, of Fayette county, Pennsylvania. The fruits of that union were a family of three children, of whom the subject of this sketch is the youngest. Mrs. McWilliams died about the year 1808. Her husband was married to his second wife, a short time afterwards, by whom he had a family of eleven children. Mr. McWilliams died at the age of 65, at his residence, in Ohio, where he had moved. The subject of this sketch received most of his education in the schools of Ohio. Previous to his marriage, his time was largely employed on his father's farm. In 1824, he was married to Miss Margaret, daughter of Alexander Latimer, formerly of Scotland. They had a family of eight children, only four of whom are now living. In 1834 Mr. McWilliams removed to Illinois, landing at Naples, where he spent the winter. The spring following, he located on a farm near Griggsville, Pike county. On the 28th day of December, 1838, his wife died at their residence. In June, 1839 he was married to his present wife, then Miss Lucretia Prescott, who is a native of Groton, Massachusetts.
In 1838, Mr. McWilliams was elected to a seat in the legislature of Illinois as representative from Pike county, being the democratic candidate, where he served a term of two years. The first session was held at Vandalia, and the second at Springfield. In 1848, Mr. McWilliams engaged in the lumber trade, which business he has since carried on. During the war he was a staunch supporter of the administration, and advocated a bold and decisive prosecution of the war. His son, Capt. John McWilliams, served for ninety days in the 8th regiment of Illinois volunteers, commanded by Col. Ogelsby. Immediately after returning home, he re-enlisted, and was with Sherman during his celebrated march to the sea. At present, Mr. McWilliams is residing at his beautiful residence in Griggsville, enjoying excellent health.