The letter is U

Emmett Typolt to Paige Udell
John Uden to N Uhde
S Uhde to Dona Ullman
Duane Ullman to Joy Ulrich
Judy Ulrich to Randy Umback
Rick Umback to Lonnie Underhill
Robert Underkofler to Bryce Unger
Ed Unger to Eric Unruh
Ervin Unruh to Bernadette Upham
Chick Upham to L Urban
Faye Urbanski to Jamie Urness
Horst Urology to Kim Utick