A denomination will help with a answer. Please re-post with more information
The Liberty head design was used on over several different coins in 1878. Please post a new question with the coin's denomination, with the wording "What is the value of an 1878 US (coin denomination)?" e.g. What is the value of an 1878 US silver dollar? or What is the value of an 1878 US 10 dollar gold piece.
For an accurate assessment of value the coin needs to be seen. Take it to a coin dealer for a idea of value.
It is not very easy to find out the value of a 1878 morgan silver dollar, because the value varies from $20 to $46000 which depends on the condition of the coin. A specialist could help to find the value of this coin.
The US didn't mint any nickels in 1878. Please check your coin again.
$30.00 to $40.00
The Philadelphia issue (no mintmark) 1878 Trade Dollar is a Proof only coin with a retail value of about $1,000.00 but take it to a dealer for a assessment.
Assuming the coin is circulated and still in collectible condition. The 1878-S Morgan dollar is worth from $31.00-$44.00 depending on the grade of the coin.
Current retail value for this coin is $17.00-$26.00 for a circulated example
The Philadelphia issue (no mintmark) 1878 Trade Dollar is a Proof only issue. The coins have a retail value of about $1,000.00. Take it to a coin dealer for an assessment.
To determine the exact value of an 1878 Goloid metric coin, a few different factors would need to be considered. Some of these factors would be the authenticity and condition of the coin.
Several different varieties (5) of 1878 Morgan dollars were made and values run from $17.00-$75.00 depending on type and how much wear the coin has. So take it to a coin dealer for a better idea of value.
The Philadelphia issue (no mintmark) 1878 Trade Dollar is a Proof only coin with a retail value of about $1,000.00 but take it to a dealer for a assessment.