John Glenn (1921–2016)

Family background and the documented, specific Ulster-Scots ancestral connection — the 1751 birth of great-great-grandfather David Glenn in Coleraine, County Londonderry, his marriage to Nancy Dunlap of County Monaghan, and the family's subsequent generations in Pennsylvania and Ohio — are drawn from detailed genealogical research using US census, birth, and marriage records. This article states plainly that no ancestor in the documented family tree, on either side, was born in Scotland itself; the connection is Ulster-Scots, several generations removed from Scotland, consistent with how this series treats other Ulster-Scots figures. Early life, military service, the Mercury program and Friendship 7, Senate career, the Keating Five controversy, the 1998 shuttle flight, and death are drawn from Wikipedia's published research record.

An Ulster-Scots origin recovered through deeper genealogical research

This article names John Glenn's ancestry with real specificity rather than the vague or absent claim found in most of his standard biographies: his paternal great-great-grandfather, David Glenn, was born in Coleraine, County Londonderry, Ulster, in 1751, and married Nancy Dunlap of County Monaghan. This article states this because it represents a documented, dated, place-specific ancestral connection uncovered through deeper genealogical research than Glenn's own Wikipedia biography provides — consistent with how this series treats other Ulster-Scots figures such as James Buchanan, Andrew Jackson, John C. Calhoun, Henry Knox, James G. Blaine, John C. Breckinridge, and Thomas McKean, whose Scottish connections likewise run through Ulster rather than directly from Scotland.

An honest distinction between Ulster-Scots and Scotland-born ancestry

This article states plainly that no ancestor in Glenn's documented family tree was born in Scotland itself; every traceable line runs through Ulster, Pennsylvania, or Ohio. This article names this distinction because Ulster-Scots communities historically understood themselves as ethnically and culturally Scottish — descendants of Lowland Scottish Presbyterians planted into Ulster in the early 17th century, who in America actively distinguished their "Scotch-Irish" identity from Irish Catholic immigrants — even though the immediate emigrating generation was Ulster-born rather than Scotland-born. This article treats that identity as a legitimate, documented form of Scottish diaspora, consistent with the standard applied throughout this series, while stating the genealogical facts precisely rather than overstating them.

A historic spaceflight achievement named with its real scale

This article states the precise, documented scope of Glenn's most famous achievement: three orbits of the Earth in just under five hours aboard Friendship 7 on 20 February 1962, making him the first American to achieve orbital spaceflight. This article names this because it represents a concrete, historically verified milestone, not a general claim of space-program involvement.

A documented Senate controversy stated without minimisation

This article states directly the real, documented controversy that marked part of Glenn's long Senate career: his involvement as one of the "Keating Five" senators investigated for intervening with federal regulators on behalf of a savings-and-loan executive facing fraud charges, resulting in a formal Senate Ethics Committee reprimand for "poor judgment." This article names this because omitting it would present Glenn's 24-year Senate career as free of serious scrutiny, when the historical record includes this documented episode.

• John Glenn's great-great-grandfather, David Glenn, was born in Coleraine, County Londonderry, Ulster, in 1751 — a documented Ulster-Scots connection only surfaced through deeper genealogical research, since his standard biographies omit any ancestry discussion.
• No ancestor in Glenn's documented family tree was born in Scotland itself; the family's traceable line runs through Ulster, then Pennsylvania and Ohio for every generation since.
• Glenn shot down three MiG-15 fighter jets during the Korean War, in addition to flying 57 combat missions in the Pacific during World War II.
• Glenn made the first supersonic transcontinental flight across the United States in 1957.
• At age 77, Glenn became the oldest person ever to fly in space, aboard Space Shuttle Discovery in 1998.
• Glenn was one of the "Keating Five" senators formally reprimanded by the Senate Ethics Committee during a 1980s savings-and-loan scandal investigation.
• Glenn was the last surviving member of the original Mercury Seven astronauts when he died in 2016.

• Clarification: This article does not claim John Glenn had a Scotland-born ancestor; his documented connection is Ulster-Scots, tracing to a great-great-grandfather born in Coleraine, County Londonderry, Ulster, in 1751. This article treats that Ulster-Scots ancestry as a legitimate form of Scottish diaspora, consistent with how this series treats other Ulster-Scots figures, while stating the genealogical facts precisely.
• Content note: This article states the "Keating Five" Senate ethics controversy directly, rather than presenting Glenn's long Senate career as free of scrutiny.