[3] He was born in Reading, Massachusetts, to William Henry Willcox, a congregational minister,[2] and Anne Holmes Goodenow.
(The main section, by Thomas Athol Joyce, is of interest today for the insight it gives into racial prejudices of the time.)
Emil Julius Gumbel described his body of work, collected in Studies in American Demography, as "the type of old-fashioned writings which will continue to be of value notwithstanding all progress achieved in mathematical statistics.
Perpetuating ideas of race suicide, Willcox erroneously explained that the United States' birth rate meant that importing babies from France would be the only option for maintaining population levels.
[9] After serving as one of five chief statisticians for the U.S. Census in 1900,[10][11] Willcox proved that for any method of apportionment that involves rounding, a priority list can be created by dividing the rounding point into each state's population,[12] by which each seat can be assigned in successive order based on each state's priority listings.
[2] In 1947, Willcox served a short term as the president of the International Statistical Institute.