Eastern, other directions in US and Canada

Time zones: both countries have Eastern time zones, as well as Central, Mountain, and Pacific. But the Eastern time zone is NOT the easternmost. That distinction goes to Newfoundland time in Canada. In the US, there are zones for Alaska and Hawaii-Aleutian, the latter the islands of Alaska.

Extreme points:

Northernmost point: Point Barrow, Alaska 71°23′ N, 156°29′ W
Easternmost point: West Quoddy Head, Maine 44°49′ N, 66°57′ W
Southernmost point: Ka Lae (South Cape), Hawaii 18°55′ N, 155°41′ W
Westernmost point: Cape Wrangell, Alaska (Attu Island) 52°55′ N, 172°27′ E

But there’s a big caveat here: These are measured from the geographic center of United States (including Alaska and Hawaii), west of Castle Rock, S.D., 44°58′ N, 103°46′ W. If measured from the prime meridian in Greenwich, England, Cape Wrangell, Attu Island, Alaska, would be the easternmost point, because Attu is on the other side of the International Date Line.

If you just count the contiguous 48 states:

Northernmost point: Northwest Angle Inlet in Lake of the Woods, Minnesota 49°23′04.1″N, 95°9′12.2″W – because of incomplete information at the time of the Treaty of Paris (1783) settling the American Revolutionary War.
Easternmost point: still West Quoddy Head, Maine 44°48′55.4″N, 66°56′59.2″W
Southernmost point: Western Dry Rocks, Florida 24°26.8′N 81°55.6′W, In the Florida Keys – occasionally above water at low tide; Ballast Key, Florida 24°31′15″N 81°57′49″W – continuously above water
Westernmost point: Cape Alava, Washington 48°9′51″N, 124°43′59″W

For Canada:

Northernmost point — Cape Columbia, Ellesmere Island, Nunavut 83°6′41″N, 69°57′30″W
Southernmost point — South point of Middle Island, Ontario, in Lake Erie 41°40′53″N, 82°40′56″W
Easternmost point — Cape Spear, Newfoundland 47°31′25″N, 52°37′10″W
Westernmost point — Boundary Peak 187,[1] Yukon 60°18′23″N, 141°0′7″W

The Eastern United States can be defined as east of the Mississippi River. It is further delineated by the designations of the map, which are hardly standardized.