Samuel Pasco, a Democrat, was elected by the Legislature of the State of FLORIDA to the Class 1 seat (term: 4 March 1887 to 3 March 1893) before the convening of the "long" session of the 50th Congress on 5 December 1887. Senator Pasco, therefore, is counted among the 37 Democrats elected to the Senate of the 50th Congress, notwithstanding the existence of a vacancy at the start of that Congress [4 March 1887] due to a failure of the legislature to elect.

The Class 2 Senate seat from NEW HAMPSHIRE (term ending 3 March 1889) was vacated by the death of Senator Austin F. Pike on 8 October 1886, during the preceding Congress; the Governor of the State appointed Person C. Cheney, a Republican, on 24 November 1886 to fill the vacancy until a successor could be elected by the General Court of the State. Senator Cheney continued to serve into the 50th Congress by virtue of this appointment; however, William E. Chandler- also a Republican- was elected to fill this seat by the General Court of the State on 14 June 1887, before the convening of the "long" session of that Congress on 5 December 1887. Senator Chandler- and not his immediate predecessor, Senator Cheney- is, therefore, the one counted among the 39 Republicans elected to the Senate of the 50th Congress.