What are the most common last name initials in the US?

The most common last name initials in the U.S. are often found to be S, J, and M. This trend reflects the prevalence of surnames like Smith, Johnson, and Miller. Other frequently occurring initials include B, W, and C, which correspond to popular last names such as Brown, Williams, and Clark. Overall, the distribution of last name initials can vary by region and demographic factors.