Quincy left Congress because he saw that the Federalist opposition was useless.

Entity and relation annotations:
id: 0
type: entity
value: text: Quincy
labels: <Person>
id: 1
type: entity
value: text: the Federalist opposition
labels: <Organization>
id: 2
type: entity
value: text: Congress
labels: <Organization>
type: relation
to_id: 2
labels: Person:leaves:Organization
from_id: 0