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).
Leonidas
Leonidas has been climbing in recent years. All-time it's been given to 10,281 U.S. babies, the 902nd most common name by sound today, peaking at 760 in 2022, with 591 in 2025.
Leonidas has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).