What effect did the presence of Union troops have in the South after the Reconstruction Act of 1867?

The presence of Union troops in the South after the Reconstruction Act of 1867 was primarily aimed at enforcing compliance with federal laws and regulations, particularly those related to the Reconstruction efforts. These troops were deployed to oversee the implementation of new policies intended to rebuild the South and promote civil rights for newly freed African Americans, including the protection of their voting rights.

Union troops played a critical role in maintaining order and stability during a period marked by significant upheaval and resistance to these reforms. Their presence helped to deter violent backlash from groups opposed to Reconstruction, such as the Ku Klux Klan, and served to support the efforts of local governments aligned with federal policies. By ensuring that Southern states adhered to the guidelines set forth by Congress, including the ratification of the Fourteenth and Fifteenth Amendments, the Union troops were instrumental in the federal government's attempts to create a more equitable society in the post-Civil War South.

In contrast, the remaining options misinterpret the impact of Union troops. While the presence of troops might have led to friction, it did not establish lasting peace, encourage secession, or diminish federal control; rather, it reinforced federal authority during a challenging transitional period.