what topic is rarely discussed in the journals and letters home written by those who traveled the oregon trail

Indian attacks

Explanation:

Remember, this were home written by those who actually travelled the Oregon trail and so they portrayed the actual conditions.

Admittedly, there were attacks in the Oregon trail by Indians, however, this attacks were rare since in most cases travelers were having a travel guide. Also, this travellers were faced with other bigger problems like the threat of cholera and other diseases which killed thousands.

a low four-wheeled open carriage of a kind formerly used in russia.