How to read the band →
Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Glenn
Glenn is now well below its former popularity. All-time it's been given to 377,832 U.S. babies, the 1,765th most common name by sound today, peaking at 10,242 in 1962, with 198 in 2025.
By sound, Glenn also includes the spellings Glen.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).