Surname distribution maps for Dreyfus
Dreyfus in the 1881 Census
Dreyfus in the 21st Century
The maps, if available, show both where there are more people named Dreyfus and where they are most concentrated.
The darker the colour, the more people in that county are named Dreyfus.
The larger the dot, the greater the proportion of people in that county are named Dreyfus.
Hovering over the dots will give you the individual statistics for that county.