Table:
0
A
B
C
D
E
1
State (class)
Vacator
Reason for change
Successor
Date of successors formal installation
2
New Hampshire (2)
Vacant
Legislature failed to elect on time.
John Parker Hale (R)
July 30, 1855
3
Alabama (3)
Vacant
Legislature failed to elect on time.
Benjamin Fitzpatrick (D)
November 26, 1855
4
Pennsylvania (3)
Vacant
Legislature failed to elect on time.
William Bigler (D)
January 14, 1856
5
California (3)
Vacant
Legislature failed to elect on time.
William M. Gwin (D)
January 13, 1857
6
Indiana (3)
Vacant
Legislature failed to elect on time.
Graham N. Fitch (D)
February 4, 1857

Questions and formulas:
Question: What state had william bigler (d) as a successor)
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,D1="William Bigler (D)"),1))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E6,D2:D6="William Bigler (D)"),1))
Level: medium