What was the effect of the emancipation proclamation on the numbers of men choosing to join the union army?

The Effect: After the Emancipation Proclamation was issued thousands of slaves were freed from ten Confederate states that were in rebellion. The Proclamation also allowed African Americans to join the Union army and help fight the Confederates which increased the Union's numbers by about 200,000.

Explanation:

The Emancipation Proclamation, or Proclamation 95, was a presidential proclamation and executive order issued by United States President Abraham Lincoln effective January 1, 1863. It changed the legal status under federal law of more than 3.5 million enslaved African Americans in the Confederate states from slave to free. As soon as a slave escaped the control of the Confederate government, either by running away across Union lines or through the advance of federal troops, the slave was free. Ultimately, the Union victory brought the proclamation into effect in all of the former Confederacy. The remaining slaves, those in the areas not in revolt, were freed by state action, or by the Thirteenth Amendment to the United States Constitution, ratified in December 1865.

they change the constitution.