What union is it ?

This union accepted skilled as well as unskilled workers, blacks as well as whites, and men as well as women. As a result, its membership grew quite rapidly.

I don't know. What does your text say? Which unions are options, and when?

I agree with Reed, when? which unions? My guess is it might be focusing on this movement https://en.wikipedia.org/wiki/Congress_of_Industrial_Organizations#History however, there are other union movements that could fit in other time periods. Repost the question if you need more help.

To determine what union is being referred to, we can analyze the information provided. The key characteristics of the union mentioned are:

1. Accepting both skilled and unskilled workers: This indicates that it is an inclusive union, not limited to a specific skill level.

2. Accepting both blacks and whites: This suggests that the union is committed to racial equality and does not discriminate based on race.

3. Accepting both men and women: This implies that the union supports gender equality and allows membership from individuals of all genders.

With these traits in mind, it is possible that the union being referred to is the Industrial Workers of the World (IWW) or the Congress of Industrial Organizations (CIO). Both of these unions were known for their inclusive practices, accepting workers from diverse backgrounds regardless of race, skill level, or gender. However, without more specific information, it is difficult to determine the exact union being discussed.