In 1867, why did congressional republicans enact a more aggressive plan for
reconstruction, including sending federal troops into the south?
a. rebuilding proved more difficult than expected, and southern states requested additional
from the government.
b. after president lincoln's assassination, congress wanted to take steps to complete the plan he
had started.
c. andrew johnson advocated ending reconstruction, and congress wanted to use his viewpoint
as a basis for impeachment.
d. southern state governments had taken steps to keep former slaves in inferior political, social,
and economic statuses.

In 1867, Congressional Republicans enact a more aggressive plan for Southern state governments had taken steps to keep former slaves in inferior political, social,  and economic statuses.

Explanation:

In 1866, the Joint Committee on Reconstruction concluded that, by withdrawing, the southern states had abandoned “all civil and political rights under the Constitution.” The Committee refused President Johnson’s Reconstruction plan, a deserted arrangement of southern legislators, and claimed that only Congress could conclude how Reconstruction would take place.

Northern Republicans did not require to yield up the political authority they existed, particularly by providing prior Confederate leaders to reform their seats in Congress. Since the South did not engage in Congress from 1861 to 1865, Republicans were able to pass legislation that approved the North. Republicans were also concerned that the South’s congressional design would develop since workers were no extended recognized only three-fifths of a person. This people's development would shift the congressional authority to the South, permitting them to immortalize the Black Codes and virtually re-enslave blacks.

a widespread disease that killed many people

the split of the christian church

invasion from arab muslims