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).
Arthur
Arthur has been climbing back after years of decline. All-time it's been given to 556,970 U.S. babies, the 230th most common name by sound today, peaking at 10,689 in 1921, with 3,852 in 2025.
By sound, Arthur also includes the spellings Arther.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).