What 19th century invention is said to have “freed the artist” to create

Impressionism, abstractionism, and surrealism were inventions that freed the artist in the 19th century but Impressionism was the key to that liberation.

Explanation:

All right, first of all, a little bit of context. After the enlightenment and the high strict art scheme of realism many artists felt chained to rules, to models, and schemes. So, they kept ideas in secret. That is why a lot of them have unknown works that are actually their best and most valuable. Thus, after impressionism and abstractionism arrived one before the other. They saw a chance to release all they had stored and everything happened. and it happened so fast that surrealism hit hard the 19th and 20th-century society with art so powerful that triggered opinions of the purists and general society because those expressions were critics against society. Impressionism was a perfect way to manifest against the rules, the molds, and it worked perfectly because artists influenced people and they imported that fight to their lives.

the french attack on germany was caused by the military alliance

the french gave their support to another tribe during he war.