IRWIN, Mathew, soldier, born in Ireland in 1740; died in Philadelphia, Pennsylvania, 10 March, 1800. He emigrated to the United States in 1767, and was a successful importer in Philadelphia till the beginning of the Revolution, when he entered the army as captain and quartermaster in the Pennsylvania line. He served in various capacities until 1783, and in December, 1777, when the army at Valley Forge was destitute of clothing and provisions, was one of sixty citizens of Philadelphia to provide funds for its temporary support, his subscription being £5,000. In 1785 he became recorder of Philadelphia, and from the adoption of the constitution of 1790 was master of rolls of the state of Pennsylvania until his death.--His son, Thomas, jurist, born in Philadelphia, 22 February, 1785; died in Pittsburg, Pennsylvania, 14 May, 1870, was educated at Franklin college, Pennsylvania, but, in consequence of the death of his father, who left a heavily encumbered estate, was not graduated. In 1804 he became editor of the "Philadelphia Repository," studied law, and in 1808 was admitted to the bar. In this year he accepted an appointment in the Indian department at Natchitoches, Louisiana, and also practised law there for two years. Failure of health necessitating his return in 1810, he settled in Uniontown, Fayette County, New York, was a member of the legislature in 1824-'6, and during his term of office framed the bill for the extension of the Chesapeake and Ohio railroad. In 1828 he was elected to congress as a Democrat, serving till his appointment in 1830 as judge of the western district of Pennsylvania, which office he held till his death. His opinion regarding the fugitive-slave act of 1850 had a large circulation.