While this is a single family that makes up the order Falconiformes, there are actually three subfamilies that make up the family Falconidae.
Those subfamilies are Herpetotherinae (laughing falcon & forest falcons), Polyborinae (caracaras & the spotted-winged falconet), and Falconinae (falcons, kestrels, and other falconets).

They are absent from Antarctica, the northern most regions of the Arctic, some of the more remote islands, and the inner dense regions of forests within central Africa.
The most cosmopolitan member of the family is the peregrine falcon–which can be spotted from Greenland to Fiji.
There are two difference between the Falconidae family and the Accipitridae family. Those differences include eye color: the eyes of the Falconidae family are brown, while the eyes of the Accipitridae family are golden in color. The second difference is the method of killing–they kill their prey with their beaks and not their talons.
There are at least two species that have gone extinct over the past 150 years: the Guadalupe Caracara and the Reunion Kestrel. Numerous other species are listed as vulnerable, near-threatened, or threatened.
Family members that can be seen within US/Canada/Mexico include:
Aplomado Falcon
American Kestrel
Merlin
Peregrine Falcon
Gryfalcon
Prairie Falcon
Crested Caracara
The photography goals for the family are similar to the goals for the order: get a picture of a member on different continents (South America, Europe, Asia, Africa, and Australia), plus get a picture of each member that can be spotted within US and Canada.
References: https://nhpbs.org/wild/falconidae.asp and https://en.wikipedia.org/wiki/falconidae