The Japanese famously brought the United States into World War Two on the 7th of December 1941. At the same time Japan launched a massive invasion across the Pacific, however that was on the other side of the date line, so the war started on the 8th.
USMC Embassy guard in 1938
At 0800, 1000 Japanese soldiers surrounded a United States Marine Corps barracks at Tientsin in North China. These marines were part of the embassy guards. Overhead three Japanese planes circled lazily. A Japanese officer called Major Omura marched up to the marine sentry and asked to speak to the Barracks Commander, a Major Luther Brown. Maj. Brown knew Maj. Omura, and his superior Lieutenant General Kyoji Tominaga very well. Maj. Brown had socialised with both before the sudden outbreak of hostilities and counted both as friends.

Maj. Omura had a written proposal. It asked the Marines to surrender at one location, after stacking weapons at another. The alternative was for the Japanese to enforce their demands with the troops they had available.

After a telephone call to the Commander of the Embassy Guard in Beijing (Colonel William Ashurst), Maj. Brown agreed. He believed that his marines would be counted as consular officials and would be repatriated to the US. Due to a diplomatic misunderstanding between the two sides the matter of repatriation was never concluded. At first the US had insisted on the marines return, however the Japanese considered them a military unit. The US response was "that the matter would be decided at a later date."
Col Ashurst arriving to surrender
On January 27th 1942 both groups of marine guards were detained at the same location in Shanghai. They were informed they were not to be repatriated as there was no space left on the exchange ships. There were significant issues with the exchange, including space, which threw the entire operation into jeopardy. So it is possible the excuse given to the marines was true.

At the start of February the marines were moved to Woosung Camp. The camp already held the USMC prisoners taken at Wake Island, who had been there since the 24th of January. Woosung was a 20 acre camp enclosed by an electric fence. A second electric fence enclosed the prisoners accommodation and the parade ground. The accommodation was seven wooden frame buildings that were poorly built. Each had an attached toilet and washroom.
North China Marines inside their barracks
The poor state of the barracks was of real concern due to the bitter winter. In the end the marines took to sleeping four to a single bunk, pooling all of their blankets to avoid freezing to death. During the day when they marched out for exercise periods the marines had to wrap the blankets around their shoulders. However, one of the civilian interpreters nicknamed the "Beast of the East" soon put a stop to that.

The despicable treatment of POW's by Japanese forces has often been described as being caused by the Japanese code of honour. However the explanation has always seemed too simple to me. A better understanding of the situation comes from piecing together the following information. The POW's were forced to sign a document that said they had joined the Imperial Japanese Army. Life in the IJA was incredibly brutal, with beatings and violence a daily occurrence. One marine at Woosung recounts how he saw a NCO punch a private in the face. The private then had to bow, when he straightened up he was punched again. This punishment continued for some time. POW's were therefore seen as the lowest rank of the army, and they had committed what the IJA considered gross misconduct by being captured. Add in the language barrier and you may well get an inkling of why the POW's of the Japanese were treated so badly.

There were also civilian staff, one of which was Isamu Ishihara, who was considered the most brutal of all the guards. Ishihara had been a taxi driver before the war, and had learnt English in the United States. At Woosung he acted as an interpreter. Despite his brutality, and later arrest in 1945 for war crimes, Ishihara didn't have things all his own way.

One day Ishihara flew into a rage, the subject of his displeasure was Sir Mark Young, the British governor of Hong Kong. Pulling his sword Ishihara advanced on the old man. Maj. Brown leapt into action, he ripped the Katana from Ishihara's hands, and shoved him away from Sir Young.
Sir Young
Shortly afterwards The Japanese second in command, Captain Endo, appeared on the scene. After hearing what had happened Maj. Brown was given no punishment, and Ishihara was beaten with a two by four, and banned from carrying arms.

Another incident concerning Ishihara was when he punched a marine Sergeant, the marine punched back and floored Ishihara. When Ishihara struggled to his feet, he walked up to the marine and placed his hand on his shoulder and told him he was a good prisoner. The marine later won an award for being a model POW.

Finally, after months of appeals by the Red Cross and the USMC commanding officer the marines were moved to Kiangwan, a camp with better conditions. There they remained until March 1945. About then the marines started to hear rumours that they were once again about to be moved. So they started preparing by stockpiling food and supplies.
The North China Marines on the way to Woosung
On May the 8th the Japanese used the prisoners to make modifications to railway cars to transport them. A few marines started making plans for escape, and managed to get included in the work party. The rolling stock selected were boxcars with sliding doors in the middle. The working party was to install an oil drum as a toilet, cover the windows with barbed wire, and place a blackout on each window.

The two ends of the box car were turned into compounds by more barbed wire stretched between the walls, with the area in between the doors having four Japanese guards stationed there.

After much arguing the marines managed to convince the Japanese that the oil drum used as a toilet should be enclosed for privacy. Some doors were provided and were installed enclosing the toilet, and incidentally the window. The barbed wire over the window was placed in a way that made it look like it was fastened, when it really wasn't. Rungs under the window would allow a prisoner to hold on until joined by a second, so they could jump in pairs. With these preparations in place, the marines formed a plan.

First Lieutenants John Kinney and John McAlister who didn't speak any Chinese would pair up with First Lieutenants Richard Huizenga and James McBrayer, both of whom did speak Chinese. All were provided with cards with Chinese phrases written on them, which they could point to in an effort to communicate with the locals should the pairs be split up.

On the 9th of May the prisoners were marched down and boarded the train. Despite their best efforts the escapees weren't put in the prepared box car. After a days travelling the train reached Nanking, the next night the marines started their plan. Whenever they could members of the group would slip to visit the oil drum, and working carefully they managed to free the wire from inside. Whilst the guards were distracted by their supper the escapees managed to slip out the window.
The first problem was there were no metal rungs on the outside, so all the officers had to leap on their own. The train was rocketing along at about 40mph, each escapee had to leap into the darkness not knowing what they were about to hit. Although bruised and battered, and spread out over several miles all four were able to walk.

After a few hours skulking through the countryside hiding from Japanese patrols each of the four officers made contact with Chinese communist guerrillas. All four were re-united at one location shortly afterwards. Then a fifth American called Lewis Bishop was brought in! Originally he had been with the Flying Tigers before being captured. He had been in the same box car as the four marines, and seeing what was going on, and spotting a chance he had gotten out.

The four became local celebrities, handed from one group of fighters to the next. As they made their way through China towards friendly forces the Chinese units held rallies in their honour. At each they were asked to sing the United States National Anthem. However, all five of them didn't really know the words so they decided to improvise.

So its likely that for many years after the war parts of China thought the that the Marine Corps Hymn, the Halls of Montezuma, is the United States National Anthem.

The five escapees reached friendly territory on June the 16th, and officially got a home run.