This was probably the strongest tournament ever held up until that time. The tournament lasted from July 18th to August 4th and consisted of ten masters playing a double round robin.
The day after the tournament began, on July 19th, France declared war on Prussia and the southern German states, including the Grand Duchy of Baden, took the side of Prussia and its North German allies. At the outbreak of the war there was much discussion between the players as to whether or not the tournament should continue. The reason was because Baden-Baden is not far from the French border and there was a real possibility that the town could be occupied by the French. In the end the players opted to continue although according to press reports the atmosphere was tense.
After the fourth round, as a reservist officer Adolf Stern was called to active duty. He had only played four games, losing two on time (to Steinitz and Minckwitz), winning one (against Minckwitz) and drawing one (to Steinitz). His 14 forfeited games were counted as wins for his opponents.
The finish of Baden-Baden in August was near the end of hostilities. At one time artillery fire could be heard in Baden-Baden from a distance of 18 miles.
The French town of Sedan, near the Belgian border, was the decisive battle of the war and it began on the morning of September 1, 1870. The battle continued until 4:15 PM, when Napoleon, who had just arrived in Sedan, took command. Recognizing the hopelessness of the situation, he ordered the white flag to be hoisted. Terms of surrender were negotiated during the night and on the following day Napoleon, together with 83,000 troops, surrendered to the Germans. Sedan lies 234 miles from Baden-Baden and Stern, who participated in the battle, sent a post card on September 4th saying, "Emperor Napoleon has been mated."
The two main rivals were Anderssen and Steinitz. Anderssen created a minor sensation when he defeated Steinitz in both of their games but then lost both games against Gustav Neumann.
After ten rounds Neumann was leading Anderssen and Blackburne by a half point followed by Steinitz a point behind first. Then Neumann faded, losing two games to Steinitz and one each to Rosenthal and de Vere.
Meanwhile Steinitz had come alive, scoring 5.5 points in seven rounds and going into the last round was half point behind the leader Anderssen. In the last round Steintz' opponent was de Vere against whom he could only draw.
Anderssen was paired against Louis Paulsen who had been having a poor tournament, but was still one of the best players in the world at the time. It was his last round win against Paulsen that gave Anderssen first place and it was a real slugfest!
Ludek Pachman wrote some truly great books, especially on tactics and strategy, but when he annotated this game in the entertaining Decisive Games in Chess History he did a really poor job. His brief notes were primarily based on the result and he ignored almost all the possibilities for both sides to the point that his notes were pretty much useless. A fairly common trait in many of those old books!
1) Anderssen 13.0
2) Steinitz 12.5
3-4) Neumann and Blackburne 12.0
5) Paulsen 9.5
6-7) De Vere and Winawer 8.5
8-9) Rosenthal and Minckwitz 7.0
10) Stern 1.5